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Channa KK, Venables RH, White SJ. Exploring elderly patients’ perspectives on deprescribing: a qualitative study interim analysis. International Journal of Pharmacy Practice 2022. [DOI: 10.1093/ijpp/riac021.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Introduction
The ageing population has caused an increase in polypharmacy, multimorbidities and complexity of patients (1). Polypharmacy increases the likelihood of Adverse Drug Reactions, particularly in elderly patients due to functional/cognitive changes (1). Current research investigating views on deprescribing has shown that patients are often willing to undertake deprescribing, however qualitative research in elderly populations is sparse (1).
Aim
This study aimed to explore elderly patients’ perspectives on deprescribing and pharmaceutical input into their care.
Methods
Semi-structured interviews were undertaken with a purposive sample of elderly (>65 years) inpatients with multiple morbidities and/or frailty and were taking at least one regular medicine, at two English NHS hospital Trusts. The interview guide was developed with public contributions, aligned with the study aim and informed by the Theoretical Framework of Acceptability (TFA)(2). The TFA was used because it was developed for assessing the acceptability of healthcare interventions (2). The interview guide included a distress protocol because the patient cohort was vulnerable. Interviews were conducted face-to-face, audio-recorded, transcribed verbatim and analysed using the Framework Analysis approach, with a priori categories informed by the TFA.
Results
Interviews were conducted with 8 participants (2 male,6 female), aged 67-89 and taking 3-9 pre-admission medicines. Most participants seemed to understand that deprescribing may become appropriate and trusted their doctor to initiate discussion when deprescribing is appropriate. However, participants reported wanting to know the rationale for deprescribing (TFA domain: affective attitude): “…why was I taking it in the first place if I don’t need it now?”. Most participants wanted deprescribing discussions to start with the rationale and some said medicines should be stopped gradually with regular reviews (TFA domain: affective attitude, ethicality). Most participants referred to pharmacists having a small role in their healthcare and none mentioned pharmacists stopping medicines (TFA domain: affective attitude): “… they sort all the drugs out don’t they, that they’re ordered…”. Access to GPs was commonly reported as a burden (TFA domain: burden). Some participants reported not feeling confident to ask their GP questions and some said they had not established trust due to not seeing a regular doctor (TFA domain: burden and opportunity costs): “I’ve gotta get my confidence in them…”. Several participants reported having taken medicines for years and said that they thought the medicines were beneficial, whilst other participants said that if they could take fewer medicines they would (TFA domain: ethicality and perceived effectiveness). Some participants understood that deprescribing required weighing up risks and benefits (TFA domain: intervention coherence): “…consider the benefits and the possibility of side effects”.
Conclusion
This study adds insights from qualitative research, but these may not be widely transferrable. Whilst these are interim analysis findings that may be further refined, they suggest that deprescribing is likely to be acceptable to patients when conducted by healthcare professionals they trust and who provides the rationale for deprescribing. Patients’ awareness of who can deprescribe would benefit from being increased, since participants did not cite pharmacists as experts who can deprescribe. Future research could explore how to do so.
References
(1) Reeve E, Shakib S, Hendrix I, Roberts MS, Wiese MD. Review of deprescribing processes and development of an evidence-based, patient-centred deprescribing process. Br J Clin Pharmacol. 2014 Oct;78(4):738-47.
(2) Sekhon M, Cartwright M, Francis J. Acceptability of healthcare interventions: an overview of reviews and development of a theoretical framework. BMC Health Serv Res, 2017; 17: 88.
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Affiliation(s)
- K K Channa
- Pharmacy, University Hospitals Coventry and Warwickshire, Coventry, England
| | - R H Venables
- School of Pharmacy and Bioengineering, Keele University, Keele, England
| | - S J White
- School of Pharmacy and Bioengineering, Keele University, Keele, England
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Hottentot QP, de Meijer E, Buermans HPJ, White SJ, Harteveld CL. Breakpoint characterization of a rare alpha 0 -thalassemia deletion using targeted locus amplification on genomic DNA. Int J Lab Hematol 2021; 43:1628-1634. [PMID: 34251753 PMCID: PMC9291876 DOI: 10.1111/ijlh.13651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/27/2021] [Accepted: 06/09/2021] [Indexed: 11/30/2022]
Abstract
Introduction The high‐sequence homology of the α‐globin‐gene cluster is responsible for microhomology‐mediated recombination events during meiosis, resulting in a high density of deletion breakpoints within a 10 kb region. Commonly used deletion detection methods, such as multiplex ligation‐dependent probe amplification (MLPA) and Southern blot, cannot exactly define the breakpoints. This typically requires long‐range PCR, which is not always successful. Targeted locus amplification (TLA) is a targeted enrichment method that can be used to sequence up to 70 kb of neighboring DNA sequences without prior knowledge about the target site. Methods Genomic DNA (gDNA) TLA is a technique that folds isolated DNA, ensuring that adjacent loci are in a close spatial proximity. Subsequent digestion and religation form DNA circles that are amplified using fragment‐specific inverse primers, creating a library that is suitable for Illumina sequencing. Results Here, we describe the characterization of a rare 16 771 bp deletion, utilizing gDNA TLA with a single inverse PCR primer set on one end of the breakpoint. Primers for breakpoint PCR were designed to confirm the deletion breakpoints and were consequently used to characterize the same deletion in 10 additional carriers sharing comparable hematologic data and similar MLPA results. Conclusions The gDNA TLA technology was successfully used to identify deletion breakpoints within the alpha‐globin cluster. The deletion was described only once in an earlier study as the ‐‐gb, but as it was not registered correctly in the available databases, it was not initially recognized as such.
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Affiliation(s)
- Quint P Hottentot
- Department of Clinical Genetics, Leiden University Medical Centre, Leiden, the Netherlands
| | - Emile de Meijer
- Leiden Genome Technology Centre, Leiden University Medical Centre, Leiden, the Netherlands
| | - Henk P J Buermans
- Leiden Genome Technology Centre, Leiden University Medical Centre, Leiden, the Netherlands
| | - Stefan J White
- Leiden Genome Technology Centre, Leiden University Medical Centre, Leiden, the Netherlands
| | - Cornelis L Harteveld
- Department of Clinical Genetics, Leiden University Medical Centre, Leiden, the Netherlands
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White SJ, Moore-Colyer M, Marti E, Hannant D, Gerber V, Coüetil L, Richard EA, Alcocer M. Antigen array for serological diagnosis and novel allergen identification in severe equine asthma. Sci Rep 2019; 9:15170. [PMID: 31645629 PMCID: PMC6811683 DOI: 10.1038/s41598-019-51820-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 10/08/2019] [Indexed: 01/14/2023] Open
Abstract
Severe equine asthma (sEA), which closely resembles human asthma, is a debilitating and performance-limiting allergic respiratory disorder which affects 14% of horses in the Northern Hemisphere and is associated with increased allergen-specific immunoglobulin E (IgE) against a range of environmental proteins. A comprehensive microarray platform was developed to enable the simultaneous detection of allergen-specific equine IgE in serum against a wide range of putative allergenic proteins. The microarray revealed a plethora of novel pollen, bacteria, mould and arthropod proteins significant in the aetiology of sEA. Moreover, the analyses revealed an association between sEA-affected horses and IgE antibodies specific for proteins derived from latex, which has traditionally been ubiquitous to the horse’s environment in the form of riding surfaces and race tracks. Further work is required to establish the involvement of latex proteins in sEA as a potential risk factor. This work demonstrates a novel and rapid approach to sEA diagnosis, providing a platform for tailored management and the development of allergen-specific immunotherapy.
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Affiliation(s)
- S J White
- Royal Agricultural University, Cirencester, Gloucestershire, GL7 6JS, UK. .,School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK. .,Nottingham Trent University, Brackenhurst Campus, Southwell, Nottinghamshire, NG25 0QF, UK.
| | - M Moore-Colyer
- Royal Agricultural University, Cirencester, Gloucestershire, GL7 6JS, UK
| | - E Marti
- Department of Clinical Research and Veterinary Public Health, University of Bern, Bremgartenstr, Postfach, 3001, Bern, Switzerland
| | - D Hannant
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - V Gerber
- Department of Clinical Research and Veterinary Public Health, University of Bern, Bremgartenstr, Postfach, 3001, Bern, Switzerland
| | - L Coüetil
- Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - E A Richard
- LABÉO Frank Duncombe, 1 route de Rosel, 14053, Caen, Cedex 4, France.,Normandie Univ, UniCaen, BIOTARGEN, 3 rue Nelson Mandela, 14280, Saint-Contest, France
| | - M Alcocer
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
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Frighi V, Morovat A, Andrews TM, Rana F, Stephenson MT, White SJ, Fower E, Roast J, Goodwin GM. Vitamin D, bone mineral density and risk of fracture in people with intellectual disabilities. J Intellect Disabil Res 2019; 63:357-367. [PMID: 30569589 DOI: 10.1111/jir.12581] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 10/12/2018] [Accepted: 11/16/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND People with intellectual disabilities (IDs) have very high rates of osteoporosis and fractures, to which their widespread vitamin D deficiency and other factors could contribute. We aimed to assess in people with IDs previously treated for vitamin D deficiency (1) long-term adherence to vitamin D supplementation and (2) bone mineral density (BMD), as an indicator for risk of fractures, according to vitamin D supplementation and other factors. METHOD We recorded height, weight, medical, pharmacological, dietary and lifestyle assessment. Blood sample were taken for vitamin D and related analytes. dual-energy X-ray absorptiometry for BMD was performed. RESULTS Of 51 study participants (mean [standard deviation, SD] age 51.5 [13.6] years, 57% male), 41 (80.4%) were taking vitamin D and 10 were not. Mean [SD] serum vitamin D was 81.3 [21.3] vs. 25.2 [10.2] nmol/L (P < 0.0001), respectively. Thirty-six participants underwent a dual-energy X-ray absorptiometry scan, which showed osteoporosis in 23.7% and osteopenia in 52.6%. Participants on vitamin D had higher BMD than those who were not, a statistically significant difference when confounders (lack of mobility and hypogonadism) were removed. BMD was significantly different according to mobility, particularly in wheelchair users, in whom hip BMD was 33% lower (P < 0.0001) than in participants with normal mobility. Participants still taking vitamin D showed a 6.1% increase in BMD at the spine (P = 0.003) after mean [SD] 7.4 [1.5] years vitamin D treatment. CONCLUSIONS In people with IDs and previous vitamin D deficiency, BMD increases on long-term vitamin D supplementation. However, additional strategies must be considered for osteoporosis and fracture prevention in this population.
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Affiliation(s)
- V Frighi
- Department of Psychiatry, University of Oxford, Oxford, UK
- Learning Disabilities, Oxford Health NHS Foundation Trust, Oxford, UK
| | - A Morovat
- Clinical Biochemistry, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - T M Andrews
- Department of Psychiatry, University of Oxford, Oxford, UK
- Learning Disabilities, Oxford Health NHS Foundation Trust, Oxford, UK
| | - F Rana
- Learning Disabilities, Oxford Health NHS Foundation Trust, Oxford, UK
| | - M T Stephenson
- Learning Disabilities, Oxford Health NHS Foundation Trust, Oxford, UK
| | - S J White
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | - E Fower
- Department of Radiology, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - J Roast
- Department of Learning Disabilities, Family Support Network, Didcot, Oxfordshire, UK
| | - G M Goodwin
- Department of Psychiatry, University of Oxford, Oxford, UK
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Stringer JM, Forster SC, Qu Z, Prokopuk L, O'Bryan MK, Gardner DK, White SJ, Adelson D, Western PS. Reduced PRC2 function alters male germline epigenetic programming and paternal inheritance. BMC Biol 2018; 16:104. [PMID: 30236109 PMCID: PMC6149058 DOI: 10.1186/s12915-018-0569-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 08/28/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Defining the mechanisms that establish and regulate the transmission of epigenetic information from parent to offspring is critical for understanding disease heredity. Currently, the molecular pathways that regulate epigenetic information in the germline and its transmission to offspring are poorly understood. RESULTS Here we provide evidence that Polycomb Repressive Complex 2 (PRC2) regulates paternal inheritance. Reduced PRC2 function in mice resulted in male sub-fertility and altered epigenetic and transcriptional control of retrotransposed elements in foetal male germ cells. Males with reduced PRC2 function produced offspring that over-expressed retrotransposed pseudogenes and had altered preimplantation embryo cleavage rates and cell cycle control. CONCLUSION This study reveals a novel role for the histone-modifying complex, PRC2, in paternal intergenerational transmission of epigenetic effects on offspring, with important implications for understanding disease inheritance.
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Affiliation(s)
- Jessica M Stringer
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, Victoria, 3168, Australia
- Department of Anatomy and Developmental Biology, Ovarian Biology Laboratory, Biomedicine Discovery Institute, Monash University, Melbourne, 3168, Australia
| | - Samuel C Forster
- Host-Microbiota Interactions Laboratory, Wellcome Trust Sanger Institute, Hinxton, CB10 1SA, UK
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, 3168, Australia
- Molecular and Translational Science, Monash University, Clayton, Victoria, 3168, Australia
| | - Zhipeng Qu
- Bioinformatics and Computational Genetics, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, 5005, Australia
| | - Lexie Prokopuk
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, Victoria, 3168, Australia
- Molecular and Translational Science, Monash University, Clayton, Victoria, 3168, Australia
| | - Moira K O'Bryan
- School of Biological Sciences, Monash University, Clayton, Victoria, 3168, Australia
| | - David K Gardner
- School of BioSciences, University of Melbourne, Parkville, Australia
| | - Stefan J White
- Department of Human Genetics, Leiden Genome Technology Centre, Leiden University Medical Center, Leiden, the Netherlands
| | - David Adelson
- Bioinformatics and Computational Genetics, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, 5005, Australia
| | - Patrick S Western
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, Victoria, 3168, Australia.
- Molecular and Translational Science, Monash University, Clayton, Victoria, 3168, Australia.
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Prokopuk L, Stringer JM, White CR, Vossen RHAM, White SJ, Cohen ASA, Gibson WT, Western PS. Loss of maternal EED results in postnatal overgrowth. Clin Epigenetics 2018; 10:95. [PMID: 30005706 PMCID: PMC6045828 DOI: 10.1186/s13148-018-0526-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/26/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Investigating how epigenetic information is transmitted through the mammalian germline is the key to understanding how this information impacts on health and disease susceptibility in offspring. EED is essential for regulating the repressive histone modification, histone 3 lysine 27 tri-methylation (H3K27me3) at many developmental genes. RESULTS In this study, we used oocyte-specific Zp3-Cre recombinase (Zp3Cre) to delete Eed specifically in mouse growing oocytes, permitting the study of EED function in oocytes and the impact of depleting EED in oocytes on outcomes in offspring. As EED deletion occurred only in growing oocytes and females were mated to normal wild type males, this model allowed the study of oocyte programming without confounding factors such as altered in utero environment. Loss of EED from growing oocytes resulted in a significant overgrowth phenotype that persisted into adult life. Significantly, this involved increased adiposity (total fat) and bone mineral density in offspring. Similar overgrowth occurs in humans with Cohen-Gibson (OMIM 617561) and Weaver (OMIM 277590) syndromes, that result from de novo germline mutations in EED or its co-factor EZH2, respectively. Consistent with a role for EZH2 in human oocytes, we demonstrate that de novo germline mutations in EZH2 occurred in the maternal germline in some cases of Weaver syndrome. However, deletion of Ezh2 in mouse oocytes resulted in a distinct phenotype compared to that resulting from oocyte-specific deletion of Eed. CONCLUSIONS This study provides novel evidence that altering EED-dependent oocyte programming leads to compromised offspring growth and development in the next generation.
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Affiliation(s)
- Lexie Prokopuk
- Centre for Reproductive Health, Hudson Institute of Medical Research and Department of Molecular and Translational Science, Monash University, Clayton, Victoria, 3168, Australia
| | - Jessica M Stringer
- Centre for Reproductive Health, Hudson Institute of Medical Research and Department of Molecular and Translational Science, Monash University, Clayton, Victoria, 3168, Australia.,Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
| | - Craig R White
- Centre for Geometric Biology, School of Biological Sciences, Monash University, Clayton, Victoria, 3800, Australia
| | - Rolf H A M Vossen
- Leiden Genome Technology Centre, Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Stefan J White
- Leiden Genome Technology Centre, Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Ana S A Cohen
- Department of Medical Genetics, University of British Columbia and British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada
| | - William T Gibson
- Department of Medical Genetics, University of British Columbia and British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Patrick S Western
- Centre for Reproductive Health, Hudson Institute of Medical Research and Department of Molecular and Translational Science, Monash University, Clayton, Victoria, 3168, Australia.
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White SJ, Laros JF, Bakker E, Cambon‐Thomsen A, Eden M, Leonard S, Lochmüller H, Matthijs G, Mattocks C, Patton S, Payne K, Scheffer H, Souche E, Thomassen E, Thompson R, Traeger‐Synodinos J, Vooren S, Janssen B, den Dunnen JT. Critical points for an accurate human genome analysis. Hum Mutat 2017; 38:912-921. [DOI: 10.1002/humu.23238] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 04/13/2017] [Accepted: 04/23/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Stefan J. White
- Department of Human Genetics, Leiden University Medical Center The Netherlands
| | - Jeroen F.J. Laros
- Department of Human Genetics, Leiden University Medical Center The Netherlands
- Clinical GeneticsLeiden University Medical Center The Netherlands
- GenomeScan Leiden The Netherlands
| | - Egbert Bakker
- Clinical GeneticsLeiden University Medical Center The Netherlands
| | - Anne Cambon‐Thomsen
- Epidemiology and Public Health Analyses, Inserm and Université Toulouse III Paul Sabatier Toulouse UMR 1027 France
| | - Martin Eden
- Manchester Centre for Health Economics, University of Manchester Manchester UK
| | - Samantha Leonard
- Epidemiology and Public Health Analyses, Inserm and Université Toulouse III Paul Sabatier Toulouse UMR 1027 France
| | - Hanns Lochmüller
- Institute of Genetic Medicine, Newcastle University Newcastle upon Tyne UK
| | | | | | - Simon Patton
- Central Manchester University Hospitals Foundation Trust, EMQN Manchester UK
| | - Katherine Payne
- Manchester Centre for Health Economics, University of Manchester Manchester UK
| | | | | | - Ellen Thomassen
- Department of Human Genetics, Leiden University Medical Center The Netherlands
| | - Rachel Thompson
- Institute of Genetic Medicine, Newcastle University Newcastle upon Tyne UK
| | | | | | | | - Johan T. den Dunnen
- Department of Human Genetics, Leiden University Medical Center The Netherlands
- Clinical GeneticsLeiden University Medical Center The Netherlands
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Buermans HPJ, Vossen RHAM, Anvar SY, Allard WG, Guchelaar HJ, White SJ, den Dunnen JT, Swen JJ, van der Straaten T. Flexible and Scalable Full-Length CYP2D6 Long Amplicon PacBio Sequencing. Hum Mutat 2017; 38:310-316. [PMID: 28044414 PMCID: PMC5324676 DOI: 10.1002/humu.23166] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 11/18/2016] [Accepted: 12/22/2016] [Indexed: 01/08/2023]
Abstract
Cytochrome P450 2D6 (CYP2D6) is among the most important genes involved in drug metabolism. Specific variants are associated with changes in the enzyme's amount and activity. Multiple technologies exist to determine these variants, like the AmpliChip CYP450 test, Taqman qPCR, or Second‐Generation Sequencing, however, sequence homology between cytochrome P450 genes and pseudogene CYP2D7 impairs reliable CYP2D6 genotyping, and variant phasing cannot accurately be determined using these assays. To circumvent this, we sequenced CYP2D6 using the Pacific Biosciences RSII and obtained high‐quality, full‐length, phased CYP2D6 sequences, enabling accurate variant calling and haplotyping of the entire gene‐locus including exonic, intronic, and upstream and downstream regions. Unphased diplotypes (Roche AmpliChip CYP450 test) were confirmed for 24 of the 25 samples, including gene duplications. Cases with gene deletions required additional specific assays to resolve. In total, 61 unique variants were detected, including variants that had not previously been associated with specific haplotypes. To further aid genomic analysis using standard reference sequences, we have established an LOVD‐powered CYP2D6 gene‐variant database, and added all reference haplotypes and data reported here. We conclude that our CYP2D6 genotyping approach produces reliable CYP2D6 diplotypes and reveals information about additional variants, including phasing and copy‐number variation.
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Affiliation(s)
- Henk P J Buermans
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, 2333ZC, The Netherlands
| | - Rolf H A M Vossen
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, 2333ZC, The Netherlands
| | - Seyed Yahya Anvar
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, 2333ZC, The Netherlands
| | - William G Allard
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, 2333ZC, The Netherlands
| | - Henk-Jan Guchelaar
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands
| | - Stefan J White
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, 2333ZC, The Netherlands
| | - Johan T den Dunnen
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, 2333ZC, The Netherlands.,Department of Clinical Genetics, Leiden University Medical Center, Leiden, 2333ZC, The Netherlands
| | - Jesse J Swen
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands
| | - Tahar van der Straaten
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, Leiden, 2333ZA, The Netherlands
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Abstract
Multiallelic copy number variants are genomic loci that can be present in a range of different copy numbers between individuals. High or low copy numbers of specific genes have been associated with different diseases. Precise genotyping of these loci can be complicated, and relies on accurate assays. Multiplex ligation-dependent probe amplification (MLPA) is a PCR-based approach that allows copy number determination of up to 50 genomic loci in a single reaction. In this chapter, we outline the basic protocol, with a particular emphasis on the appropriate approach to accurately genotype multiallelic copy numbers.
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Affiliation(s)
- Suzan de Boer
- Department of Anatomy & Developmental Biology, Monash University, Clayton, Australia
| | - Stefan J White
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
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10
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Abstract
Droplet digital PCR (ddPCR) is based on the isolated amplification of thousands of individual DNA molecules simultaneously, with each molecule compartmentalized in a droplet. The presence of amplified product in each droplet is indicated by a fluorescent signal, and the proportion of positive droplets allows the precise quantification of a given sequence. In this chapter we briefly outline the basis of ddPCR, and describe two different applications using the Bio-Rad QX200 system: genotyping copy number variation and quantification of Illumina sequencing libraries.
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Affiliation(s)
- Rolf H A M Vossen
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands
| | - Stefan J White
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands.
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11
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Juniarto AZ, van der Zwan YG, Santosa A, Ariani MD, Eggers S, Hersmus R, Themmen APN, Bruggenwirth HT, Wolffenbuttel KP, Sinclair A, White SJ, Looijenga LHJ, de Jong FH, Faradz SMH, Drop SLS. Hormonal evaluation in relation to phenotype and genotype in 286 patients with a disorder of sex development from Indonesia. Clin Endocrinol (Oxf) 2016; 85:247-57. [PMID: 26935236 DOI: 10.1111/cen.13051] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 01/22/2016] [Accepted: 02/28/2016] [Indexed: 12/17/2022]
Abstract
OBJECTIVE The objective of this study was to determine the aetiological spectrum of disorders of sex development (DSD) in a large cohort of underprivileged and undiagnosed patients from Indonesia. METHODS A total of 286 patients with atypical external and/or internal genitalia were evaluated using clinical, hormonal, molecular genetic and histological parameters. RESULTS The age (years) at presentation was 0-0·5 in 41 (14·3%), >0·5-12 in 181 (63·3%) and >12 in 64 cases (22·4%). 46,XY DSD was most common (68·2%, n = 195), 46,XX DSD was found in 23·4% (n = 67) and sex chromosomal DSD in 8·4% (n = 24). In 61·2% of 46,XX DSD patients, 17·9% of 46,XY DSD patients and all sex chromosome DSD patients (29·4% in total), a final diagnosis was reached based on genetic or histological gonadal tissue evaluation. 17-hydroxyprogesterone and androstenedione levels were the most distinctive parameters in 46,XX DSD patients. In 46,XY DSD, diagnostic groups were identified based on the external masculinization score: androgen action disorder (AAD), unknown male undermasculinization (UMU), and gonadal dysgenesis (GD). LH, FSH and testosterone levels were most informative especially in the older age group. HCG tests were of no additional value as no patients with androgen synthesis disorders were found. Hormonal profiles of patients with sex chromosome DSD and a Y-chromosome sequence containing karyotype showed high levels of LH and FSH, and low levels of AMH, inhibin B and testosterone compared with the normal male range. Gene mutations were found in all patients with CAH, but in only 24·5% and 1·8% of patients with AAD and UMU. In 32% of 46,XY GD patients, copy number variants of different genes were found. CONCLUSION A stepwise diagnostic approach led to a molecularly or histologically proven final diagnosis in 29·4% of the patients. The most informative parameters were serum levels of 17-hydroxyprogesterone and androstenedione in 46,XX DSD patients, and serum LH, FSH and testosterone levels in 46,XY DSD patients.
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Affiliation(s)
- A Zulfa Juniarto
- Division of Human Genetics, Center for Biomedical Research Faculty of Medicine Diponegoro University (FMDU), Semarang, Indonesia
| | - Yvonne G van der Zwan
- Department of Paediatrics, Division of Endocrinology, Sophia Children's Hospital, Erasmus University Medical Centre, Rotterdam, The Netherlands
- Department of Pathology, Josephine Nefkens Institute, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Ardy Santosa
- Department of Urology, Dr Kariadi Hospital, Semarang, Indonesia
| | - Mahayu Dewi Ariani
- Division of Human Genetics, Center for Biomedical Research Faculty of Medicine Diponegoro University (FMDU), Semarang, Indonesia
| | - Stefanie Eggers
- Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Remko Hersmus
- Department of Pathology, Josephine Nefkens Institute, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Axel P N Themmen
- Department of Internal Medicine, Section of Endocrinology, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Hennie T Bruggenwirth
- Department of Clinical Genetics, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Katja P Wolffenbuttel
- Department of Paediatric Urology, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Andrew Sinclair
- Murdoch Children's Research Institute, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Stefan J White
- Centre for Genetic Diseases, MIMR-PHI Institute of Medical Research, Monash University, Clayton, Australia
| | - Leendert H J Looijenga
- Department of Pathology, Josephine Nefkens Institute, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Frank H de Jong
- Division of Human Genetics, Center for Biomedical Research Faculty of Medicine Diponegoro University (FMDU), Semarang, Indonesia
| | - Sultana M H Faradz
- Division of Human Genetics, Center for Biomedical Research Faculty of Medicine Diponegoro University (FMDU), Semarang, Indonesia
| | - Stenvert L S Drop
- Department of Paediatrics, Division of Endocrinology, Sophia Children's Hospital, Erasmus University Medical Centre, Rotterdam, The Netherlands
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Carran EL, White SJ, Reynolds AN, Haszard JJ, Venn BJ. Acute effect of fructose intake from sugar-sweetened beverages on plasma uric acid: a randomised controlled trial. Eur J Clin Nutr 2016; 70:1034-8. [PMID: 27329612 DOI: 10.1038/ejcn.2016.112] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 05/01/2016] [Accepted: 05/24/2016] [Indexed: 01/21/2023]
Abstract
BACKGROUND/OBJECTIVE Excessive fructose intake has been linked to hyperuricaemia. Our aim was to test whether 355 and 600 ml of commercial sugar-sweetened soft drinks would acutely raise plasma uric acid. SUBJECTS/METHODS Forty-one participants were randomised to a control group or an intervention group. The control group consumed 600 ml of fructose and 600 ml of glucose beverages. The soft drink group consumed 355 and 600 ml of beverages in random order. The control beverages were matched for fructose content with 600 ml of soft drink (26.7 g). Blood samples were collected at baseline, 30 and 60 min and analysed for plasma uric acid. RESULTS Plasma uric acid concentrations were 13 (95% confidence interval: (CI): 3, 23) and 17 μmol/l (95% CI: 6, 28) higher 30 and 60 min after consumption of 600 ml of soft drink compared with the glucose control. The corresponding values for the fructose beverage were 22 (95% CI: 16, 29) and 23 μmol/l (95% CI: 14, 33). There was no significant difference in the increase in uric acid following the 600-ml soft drink compared with the fructose control at 30 min (6 μmol/l; 95% CI: -4, 15) or 60 min (5 μmol/l; 95% CI: -7, 17). There was no difference in the uric-acid-raising effect between the 355 and 600 ml volumes at 30 min (-1 μmol/l; 95% CI: -9, 6) or 60 min (-5 μmol/l; 95% CI: -10, 1). CONCLUSION Small and transient increases in plasma uric acid are likely after consumption of sucrose-sweetened commercially available single-serve soft drinks in volumes as small as 355 ml.
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Affiliation(s)
- E L Carran
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand
| | - S J White
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand
| | - A N Reynolds
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand.,Edgar Diabetes and Research Centre, University of Otago, Dunedin, New Zealand
| | - J J Haszard
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand
| | - B J Venn
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand
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Johnson J, Lee W, Frazier AE, Vaghjiani V, Laskowski A, Rodriguez AL, Cagnone GL, McKenzie M, White SJ, Nisbet DR, Thorburn DR, St. John JC. Deletion of the Complex I Subunit NDUFS4 Adversely Modulates Cellular Differentiation. Stem Cells Dev 2016; 25:239-50. [DOI: 10.1089/scd.2015.0211] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Jacqueline Johnson
- Centre for Genetic Diseases, Hudson Institute of Medical Research, Clayton, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Australia
| | - William Lee
- Centre for Genetic Diseases, Hudson Institute of Medical Research, Clayton, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Australia
| | - Ann E. Frazier
- Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, Australia
- Department of Pediatrics, University of Melbourne, Melbourne, Australia
| | - Vijesh Vaghjiani
- Centre for Genetic Diseases, Hudson Institute of Medical Research, Clayton, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Australia
| | - Adrienne Laskowski
- Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, Australia
| | | | - Gael L. Cagnone
- Centre for Genetic Diseases, Hudson Institute of Medical Research, Clayton, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Australia
| | - Matthew McKenzie
- Centre for Genetic Diseases, Hudson Institute of Medical Research, Clayton, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Australia
| | - Stefan J. White
- Centre for Genetic Diseases, Hudson Institute of Medical Research, Clayton, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Australia
| | - David R. Nisbet
- Research School of Engineering, Australian National University, Canberra, Australia
| | - David R. Thorburn
- Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, Australia
- Department of Pediatrics, University of Melbourne, Melbourne, Australia
| | - Justin C. St. John
- Centre for Genetic Diseases, Hudson Institute of Medical Research, Clayton, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Australia
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Jones SA, Toh AEJ, Odobasic D, Oudin MAV, Cheng Q, Lee JPW, White SJ, Russ BE, Infantino S, Light A, Tarlinton DM, Harris J, Morand EF. Glucocorticoid-induced leucine zipper (GILZ) inhibits B cell activation in systemic lupus erythematosus. Ann Rheum Dis 2015; 75:739-47. [PMID: 26612340 DOI: 10.1136/annrheumdis-2015-207744] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 11/01/2015] [Indexed: 01/29/2023]
Abstract
OBJECTIVES Systemic lupus erythematosus (SLE) is a serious multisystem autoimmune disease, mediated by disrupted B cell quiescence and typically treated with glucocorticoids. We studied whether B cells in SLE are regulated by the glucocorticoid-induced leucine zipper (GILZ) protein, an endogenous mediator of anti-inflammatory effects of glucocorticoids. METHODS We conducted a study of GILZ expression in blood mononuclear cells of patients with SLE, performed in vitro analyses of GILZ function in mouse and human B cells, assessed the contributions of GILZ to autoimmunity in mice, and used the nitrophenol coupled to keyhole limpet haemocyanin model of immunisation in mice. RESULTS Reduced B cell GILZ was observed in patients with SLE and lupus-prone mice, and impaired induction of GILZ in patients with SLE receiving glucocorticoids was associated with increased disease activity. GILZ was downregulated in naïve B cells upon stimulation in vitro and in germinal centre B cells, which contained less enrichment of H3K4me3 at the GILZ promoter compared with naïve and memory B cells. Mice lacking GILZ spontaneously developed lupus-like autoimmunity, and GILZ deficiency resulted in excessive B cell responses to T-dependent stimulation. Accordingly, loss of GILZ in naïve B cells allowed upregulation of multiple genes that promote the germinal centre B cell phenotype, including lupus susceptibility genes and genes involved in cell survival and proliferation. Finally, treatment of human B cells with a cell-permeable GILZ fusion protein potently suppressed their responsiveness to T-dependent stimuli. CONCLUSIONS Our findings demonstrated that GILZ is a non-redundant regulator of B cell activity, with important potential clinical implications in SLE.
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Affiliation(s)
- Sarah A Jones
- Centre for Inflammatory Diseases, School of Clinical Sciences at Monash Health, Monash University, Clayton, Melbourne, Australia
| | - Andrew E J Toh
- Centre for Inflammatory Diseases, School of Clinical Sciences at Monash Health, Monash University, Clayton, Melbourne, Australia
| | - Dragana Odobasic
- Centre for Inflammatory Diseases, School of Clinical Sciences at Monash Health, Monash University, Clayton, Melbourne, Australia
| | - Marie-Anne Virginie Oudin
- Centre for Inflammatory Diseases, School of Clinical Sciences at Monash Health, Monash University, Clayton, Melbourne, Australia
| | - Qiang Cheng
- Centre for Inflammatory Diseases, School of Clinical Sciences at Monash Health, Monash University, Clayton, Melbourne, Australia
| | - Jacinta P W Lee
- Centre for Inflammatory Diseases, School of Clinical Sciences at Monash Health, Monash University, Clayton, Melbourne, Australia
| | - Stefan J White
- Department of Human Genetics, Leiden Genome Technology Center, Leiden University Medical Center, Leiden, The Netherlands
| | - Brendan E Russ
- Department of Microbiology and Immunology, The Doherty Institute at The University of Melbourne, Parkville, Victoria, Australia
| | - Simona Infantino
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia Department of Experimental Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - Amanda Light
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia Department of Experimental Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - David M Tarlinton
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia Department of Experimental Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - James Harris
- Centre for Inflammatory Diseases, School of Clinical Sciences at Monash Health, Monash University, Clayton, Melbourne, Australia
| | - Eric F Morand
- Centre for Inflammatory Diseases, School of Clinical Sciences at Monash Health, Monash University, Clayton, Melbourne, Australia
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15
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Eggers S, DeBoer KD, van den Bergen J, Gordon L, White SJ, Jamsai D, McLachlan RI, Sinclair AH, O'Bryan MK. Copy number variation associated with meiotic arrest in idiopathic male infertility. Fertil Steril 2015; 103:214-9. [DOI: 10.1016/j.fertnstert.2014.09.030] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 09/23/2014] [Accepted: 09/23/2014] [Indexed: 12/15/2022]
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Thomas AC, Eijgelaar WJ, Daemen MJAP, Hayes EM, Bevan LA, Johnson JL, White SJ, Newby AC. P730Foam cell macrophages increase fibrosis: a new paradox. Cardiovasc Res 2014. [DOI: 10.1093/cvr/cvu098.151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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17
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van der Zwan YG, Rijlaarsdam MA, Rossello FJ, Notini AJ, de Boer S, Watkins DN, Gillis AJM, Dorssers LCJ, White SJ, Looijenga LHJ. Seminoma and embryonal carcinoma footprints identified by analysis of integrated genome-wide epigenetic and expression profiles of germ cell cancer cell lines. PLoS One 2014; 9:e98330. [PMID: 24887064 PMCID: PMC4041891 DOI: 10.1371/journal.pone.0098330] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 04/30/2014] [Indexed: 12/12/2022] Open
Abstract
Background Originating from Primordial Germ Cells/gonocytes and developing via a precursor lesion called Carcinoma In Situ (CIS), Germ Cell Cancers (GCC) are the most common cancer in young men, subdivided in seminoma (SE) and non-seminoma (NS). During physiological germ cell formation/maturation, epigenetic processes guard homeostasis by regulating the accessibility of the DNA to facilitate transcription. Epigenetic deregulation through genetic and environmental parameters (i.e. genvironment) could disrupt embryonic germ cell development, resulting in delayed or blocked maturation. This potentially facilitates the formation of CIS and progression to invasive GCC. Therefore, determining the epigenetic and functional genomic landscape in GCC cell lines could provide insight into the pathophysiology and etiology of GCC and provide guidance for targeted functional experiments. Results This study aims at identifying epigenetic footprints in SE and EC cell lines in genome-wide profiles by studying the interaction between gene expression, DNA CpG methylation and histone modifications, and their function in the pathophysiology and etiology of GCC. Two well characterized GCC-derived cell lines were compared, one representative for SE (TCam-2) and the other for EC (NCCIT). Data were acquired using the Illumina HumanHT-12-v4 (gene expression) and HumanMethylation450 BeadChip (methylation) microarrays as well as ChIP-sequencing (activating histone modifications (H3K4me3, H3K27ac)). Results indicate known germ cell markers not only to be differentiating between SE and NS at the expression level, but also in the epigenetic landscape. Conclusion The overall similarity between TCam-2/NCCIT support an erased embryonic germ cell arrested in early gonadal development as common cell of origin although the exact developmental stage from which the tumor cells are derived might differ. Indeed, subtle difference in the (integrated) epigenetic and expression profiles indicate TCam-2 to exhibit a more germ cell-like profile, whereas NCCIT shows a more pluripotent phenotype. The results provide insight into the functional genome in GCC cell lines.
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Affiliation(s)
- Yvonne G. van der Zwan
- Department of Pathology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Martin A. Rijlaarsdam
- Department of Pathology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Fernando J. Rossello
- Centre for Cancer Research, MIMR-PHI Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Amanda J. Notini
- Centre for Genetic Diseases, MIMR-PHI Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Suzan de Boer
- Centre for Genetic Diseases, MIMR-PHI Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - D. Neil Watkins
- Centre for Cancer Research, MIMR-PHI Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Ad J. M. Gillis
- Department of Pathology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Lambert C. J. Dorssers
- Department of Pathology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Stefan J. White
- Centre for Genetic Diseases, MIMR-PHI Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Leendert H. J. Looijenga
- Department of Pathology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
- * E-mail:
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Cantsilieris S, Western PS, Baird PN, White SJ. Technical considerations for genotyping multi-allelic copy number variation (CNV), in regions of segmental duplication. BMC Genomics 2014; 15:329. [PMID: 24885186 PMCID: PMC4035060 DOI: 10.1186/1471-2164-15-329] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 04/22/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Intrachromosomal segmental duplications provide the substrate for non-allelic homologous recombination, facilitating extensive copy number variation in the human genome. Many multi-copy gene families are embedded within genomic regions with high levels of sequence identity (>95%) and therefore pose considerable analytical challenges. In some cases, the complexity involved in analyzing such regions is largely underestimated. Rapid, cost effective analysis of multi-copy gene regions have typically implemented quantitative approaches, however quantitative data are not an absolute means of certainty. Therefore any technique prone to degrees of measurement error can produce ambiguous results that may lead to spurious associations with complex disease. RESULTS In this study we have focused on testing the accuracy and reproducibility of quantitative analysis techniques. With reference to the C-C Chemokine Ligand-3-like-1 (CCL3L1) gene, we performed analysis using real-time Quantitative PCR (QPCR), Multiplex Ligation-dependent Probe Amplification (MLPA) and Paralogue Ratio Test (PRT). After controlling for potential outside variables on assay performance, including DNA concentration, quality, preparation and storage conditions, we find that real-time QPCR produces data that does not cluster tightly around copy number integer values, with variation substantially greater than that of the MLPA or PRT systems. We find that the method of rounding real-time QPCR measurements can potentially lead to mis-scoring of copy number genotypes and suggest caution should be exercised in interpreting QPCR data. CONCLUSIONS We conclude that real-time QPCR is inherently prone to measurement error, even under conditions that would seem favorable for association studies. Our results indicate that potential variability in the physicochemical properties of the DNA samples cannot solely explain the poor performance exhibited by the real-time QPCR systems. We recommend that more robust approaches such as PRT or MLPA should be used to genotype multi-allelic copy number variation in disease association studies and suggest several approaches which can be implemented to ensure the quality of the copy number typing using quantitative methods.
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Affiliation(s)
- Stuart Cantsilieris
- Centre for Genetic Diseases, MIMR-PHI Institute of Medical Research, Monash University, 27-31 Wright Street, Clayton 3168, Victoria, Australia.
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Van Der Zwan YG, Stoop H, Rossello F, White SJ, Looijenga LHJ. Role of epigenetics in the etiology of germ cell cancer. Int J Dev Biol 2014; 57:299-308. [PMID: 23784841 DOI: 10.1387/ijdb.130017ll] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Embryonic development is strictly controlled by functionality of genes in which the existing networks can act both on transcription and translation regulation. Germ cell cancers (GCC) are unique because of a number of characteristics. In spite of their clinical presentation, i.e., predominantly after puberty, they arise from primordial germ cells/gonocytes that have failed appropriate maturation to either pre-spermatogonia or oogonia. GCC mimic embryonal development to a certain extent, including capacity for totipotency. This knowledge has allowed the identification of informative diagnostic markers, including OCT3/4 (POU5F1), SOX2 and SOX17. An additional marker is the overall demethylated status of the genome. Genetic mutations in GCC are rare, which is exceptional for solid cancers. Our hypothesis is that a disturbed epigenetic regulation (through combined interaction of genetic or environmental parameters; referred to as genvironment) affect embryonic germ cell development, resulting in delayed or blocked maturation, and potentially progression to GCC. In this respect, studies of patients with Disorders of Sex Development (DSD) have increased our knowledge significantly. Genvironmental influences can lead to retention of existence of embryonic germ cells, the first step in the pathogenesis of GCC, resulting into the precursor lesions gonadoblastoma or carcinoma in situ. Identification of epigenetic alterations could lead to better understanding these processes and development of specific markers for early detection, eventually leading to development of targeted treatment. This review describes an interactive model related to the role of epigenetics in GCC pathogenesis, focusing on DNA methylation, histone modifications, epigenetic memory and inheritance, as well as environmental factors.
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Affiliation(s)
- Yvonne G Van Der Zwan
- Department of Pathology, Erasmus MC- University Medical Center Rotterdam, Josephine Nefkens Institute, Rotterdam, The Netherlands
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20
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Yeung KY, Dickinson A, Donoghue JF, Polekhina G, White SJ, Grammatopoulos DK, McKenzie M, Johns TG, John JCS. The identification of mitochondrial DNA variants in glioblastoma multiforme. Acta Neuropathol Commun 2014; 2:1. [PMID: 24383468 PMCID: PMC3912901 DOI: 10.1186/2051-5960-2-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 12/07/2013] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Mitochondrial DNA (mtDNA) encodes key proteins of the electron transfer chain (ETC), which produces ATP through oxidative phosphorylation (OXPHOS) and is essential for cells to perform specialised functions. Tumor-initiating cells use aerobic glycolysis, a combination of glycolysis and low levels of OXPHOS, to promote rapid cell proliferation and tumor growth. Glioblastoma multiforme (GBM) is an aggressively malignant brain tumor and mitochondria have been proposed to play a vital role in GBM tumorigenesis. RESULTS Using next generation sequencing and high resolution melt analysis, we identified a large number of mtDNA variants within coding and non-coding regions of GBM cell lines and predicted their disease-causing potential through in silico modeling. The frequency of variants was greatest in the D-loop and origin of light strand replication in non-coding regions. ND6 was the most susceptible coding gene to mutation whilst ND4 had the highest frequency of mutation. Both genes encode subunits of complex I of the ETC. These variants were not detected in unaffected brain samples and many have not been previously reported. Depletion of HSR-GBM1 cells to varying degrees of their mtDNA followed by transplantation into immunedeficient mice resulted in the repopulation of the same variants during tumorigenesis. Likewise, de novo variants identified in other GBM cell lines were also incorporated. Nevertheless, ND4 and ND6 were still the most affected genes. We confirmed the presence of these variants in high grade gliomas. CONCLUSIONS These novel variants contribute to GBM by rendering the ETC. partially dysfunctional. This restricts metabolism to anaerobic glycolysis and promotes cell proliferation.
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Darling T, Mahfuz I, White SJ, Cheng W. No TAP63 promoter mutation is detected in bladder exstrophy-epispadias complex patients. J Pediatr Surg 2013; 48:2393-400. [PMID: 24314177 DOI: 10.1016/j.jpedsurg.2013.08.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 08/26/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUND/PURPOSE Bladder exstrophy-epispadias complex (BEEC) is thought to have a genetic component in its pathogenesis. Previously we found that p63(-/-) mice show increased ventral apoptosis and develop a BEEC phenotype. Down-regulation of the anti-apoptotic ΔNP63 and an up-regulation of pro-apoptotic TAP63 isoforms have been demonstrated in BEEC patient bladder tissues. We have previously shown that insertion/deletion polymorphisms of the ΔNp63 promoter are associated with an increased risk of BEEC. In this study, we specifically examined the TAP63 promoter to see if any sequence changes might lead to up-regulation of TAP63 and exaggerated apoptosis in BEEC patients. METHODS i) Bioinformatic analysis of the TAP63 promoter was performed to identify putative regulatory regions. ii) High-resolution Melt and Sanger sequencing was used to screen targeted regions in 112 BEEC patient DNA samples for potential sequence variants. iii) Sequence variation was analysed for significance against normal population frequency data. RESULTS i) We identified multiple epigenetic markers of transcriptional regulation within highly conserved areas of the TAP63 promoter sequence. ii) Of the 112 buccal swab DNA samples, adequate and successful screening ranged between 48 and 67 for each region. iii) No novel sequence variation or mutation was uncovered. iv) Two known SNPs were identified. However, allele frequency analysis was not statistically significant. CONCLUSION Our data do not associate genetic variation within the TAP63 promoter region with an increased risk of BEEC. Our data so far suggests that only ΔNP63 promoter aberration is involved in BEEC pathogenesis.
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Affiliation(s)
- Tom Darling
- Monash Institute of Medical Research, Monash University, Melbourne, Australia
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22
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Mahfuz I, Cheng W, White SJ. Identification of Streptococcus parasanguinis DNA contamination in human buccal DNA samples. BMC Res Notes 2013; 6:481. [PMID: 24266944 PMCID: PMC4222080 DOI: 10.1186/1756-0500-6-481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 11/14/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The use of buccal swabs in clinical and scientific studies is a very popular method of collecting DNA, due to its non-invasive nature of collection. However, contamination of the DNA sample may interfere with analysis. FINDINGS Here we report the finding of Streptococcus parasanguinis bacterial DNA contamination in human buccal DNA samples, which led to preferential amplification of bacterial sequence with PCR primers designed against human sequence. CONCLUSION Contamination of buccal-derived DNA with bacterial DNA can be significant, and may influence downstream genetic analysis. One needs to be aware of possible bacterial contamination when interpreting abnormal findings following PCR amplification of buccal swab DNA samples.
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Affiliation(s)
- Istiak Mahfuz
- Centre for Genetic Diseases, Monash Institute of Medical Research, Monash University, 27-31 Wright Street, Clayton 3168, VIC, Australia.
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Cheng Q, Fan H, Ngo D, Beaulieu E, Leung P, Lo CY, Burgess R, van der Zwan YG, White SJ, Khachigian LM, Hickey MJ, Morand EF. GILZ Overexpression Inhibits Endothelial Cell Adhesive Function through Regulation of NF-κB and MAPK Activity. J I 2013; 191:424-33. [DOI: 10.4049/jimmunol.1202662] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Cantsilieris S, Baird PN, White SJ. Molecular methods for genotyping complex copy number polymorphisms. Genomics 2013; 101:86-93. [DOI: 10.1016/j.ygeno.2012.10.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 10/23/2012] [Accepted: 10/24/2012] [Indexed: 10/27/2022]
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Hersmus R, Stoop H, Turbitt E, Oosterhuis JW, Drop SL, Sinclair AH, White SJ, Looijenga LH. SRY mutation analysis by next generation (deep) sequencing in a cohort of chromosomal Disorders of Sex Development (DSD) patients with a mosaic karyotype. BMC Med Genet 2012; 13:108. [PMID: 23157850 PMCID: PMC3538515 DOI: 10.1186/1471-2350-13-108] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 11/07/2012] [Indexed: 01/02/2023]
Abstract
Background The presence of the Y-chromosome or Y chromosome-derived material is seen in 4-60% of Turner syndrome patients (Chromosomal Disorders of Sex Development (DSD)). DSD patients with specific Y-chromosomal material in their karyotype, the GonadoBlastoma on the Y-chromosome (GBY) region, have an increased risk of developing type II germ cell tumors/cancer (GCC), most likely related to TSPY. The Sex determining Region on the Y gene (SRY) is located on the short arm of the Y-chromosome and is the crucial switch that initiates testis determination and subsequent male development. Mutations in this gene are responsible for sex reversal in approximately 10-15% of 46,XY pure gonadal dysgenesis (46,XY DSD) cases. The majority of the mutations described are located in the central HMG domain, which is involved in the binding and bending of the DNA and harbors two nuclear localization signals. SRY mutations have also been found in a small number of patients with a 45,X/46,XY karyotype and might play a role in the maldevelopment of the gonads. Methods To thoroughly investigate the presence of possible SRY gene mutations in mosaic DSD patients, we performed next generation (deep) sequencing on the genomic DNA of fourteen independent patients (twelve 45,X/46,XY, one 45,X/46,XX/46,XY, and one 46,XX/46,XY). Results and conclusions The results demonstrate that aberrations in SRY are rare in mosaic DSD patients and therefore do not play a significant role in the etiology of the disease.
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Affiliation(s)
- Remko Hersmus
- Department of Pathology, Erasmus MC, University Medical Center Rotterdam, Josephine Nefkens Institute, Daniel den Hoed Cancer Center, Rotterdam, The Netherlands
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de Boer CM, Eini R, Gillis AM, Stoop H, Looijenga LHJ, White SJ. DICER1 RNase IIIb domain mutations are infrequent in testicular germ cell tumours. BMC Res Notes 2012; 5:569. [PMID: 23068969 PMCID: PMC3503615 DOI: 10.1186/1756-0500-5-569] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 10/08/2012] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Testicular Germ Cell Tumours (TGCT) are the most frequently occurring malignancy in males from 15-45 years of age. They are derived from germ cells unable to undergo physiological maturation, although the genetic basis for this is poorly understood. A recent report showed that mutations in the RNase IIIb domain of DICER1, a micro-RNA (miRNA) processing enzyme, are common in non-epithelial ovarian cancers. DICER1 mutations were found in 60% of Sertoli-Leydig cell tumours, clustering in four codons encoding metal-binding sites. Additional analysis of 14 TGCT DNA samples identified one case that also contained a mutation at one of these sites. FINDINGS A number of previous studies have shown that DICER1 mutations are found in <1% of most cancers. To provide a more accurate estimate of the frequency of such mutations in TGCTs, we have analysed 96 TGCT samples using high resolution melting curve analysis for sequence variants in these four codons. Although we did not detect any mutations in any of these sites, we did identify a novel mutation (c.1725 R>Q) within the RNase IIIb domain in one TGCT sample, which was predicted to disturb DICER1 function. CONCLUSION Overall our findings suggest a mutation frequency in TGCTs of ~1%. We conclude therefore that hot-spot mutations, frequently seen in Sertoli-Leydig cell tumours, are not common in TGCTs.
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Affiliation(s)
- Carmela M de Boer
- Center for Reproduction and Development, Monash Institute of Medical Research, Monash University, Clayton, Australia
| | - Ronak Eini
- Department of Pathology, Erasmus MC, University Medical Center Rotterdam, Josephine Nefkens Institute, Rotterdam, The Netherlands
| | - Ad M Gillis
- Department of Pathology, Erasmus MC, University Medical Center Rotterdam, Josephine Nefkens Institute, Rotterdam, The Netherlands
| | - Hans Stoop
- Department of Pathology, Erasmus MC, University Medical Center Rotterdam, Josephine Nefkens Institute, Rotterdam, The Netherlands
| | - Leendert HJ Looijenga
- Department of Pathology, Erasmus MC, University Medical Center Rotterdam, Josephine Nefkens Institute, Rotterdam, The Netherlands
| | - Stefan J White
- Center for Reproduction and Development, Monash Institute of Medical Research, Monash University, Clayton, Australia
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Cantsilieris S, White SJ. Correlating multiallelic copy number polymorphisms with disease susceptibility. Hum Mutat 2012; 34:1-13. [PMID: 22837109 DOI: 10.1002/humu.22172] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 07/13/2012] [Indexed: 01/20/2023]
Abstract
The human genome contains a significant amount of sequence variation, from single nucleotide polymorphisms to large stretches of DNA that may be present in a range of different copies between individuals. Several such regions are variable in >1% of the population (referred to as copy number polymorphisms or CNPs), and many studies have looked for associations between the copy number of genes within multiallelic CNPs and disease susceptibility. Associations have indeed been described for several genes, including the β-defensins (DEFB4, DEFB103, DEFB104), chemokine ligand 3 like 1 (CCL3L1), Fc gamma receptor 3B (FCGR3B), and complement component C4 (C4). However, follow-up replication in independent cohorts has failed to reproduce a number of these associations. It is clear that replicated associations such as those between C4 and systemic lupus erythematosus, and β-defensin and psoriasis, have used robust genotyping methodologies. Technical issues associated with genotyping sequences of high identity may therefore account for failure to replicate other associations. Here, we compare and contrast the most popular approaches that have been used to genotype CNPs, describe how they have been applied in different situations, and discuss potential reasons for the difficulty in reproducibly linking multiallelic CNPs to complex diseases.
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Affiliation(s)
- Stuart Cantsilieris
- Centre for Reproduction and Development, Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia
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Qureshi IZ, White SJ. Differential immunolocalization of sulfonylurea receptors in mouse and rat ureters. Anat Histol Embryol 2012; 42:72-8. [PMID: 22694596 DOI: 10.1111/j.1439-0264.2012.01168.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 05/01/2012] [Indexed: 11/26/2022]
Abstract
The receptors for sulphonylurea (SURs) are known to be expressed in the mouse kidney, but their expression in the ureter is undefined. Owing to the physiological and pharmacological significance of SURs, the localization of SUR in ureters of adult mice and rats was investigated through immunohistochemistry. Animals were perfused transcardially with 4% paraformaldehyde and tissues were processed for immunohistochemistry using polyclonal antisera against SUR2A and SUR2B (SUR1) receptor proteins. Sections were incubated with primary and secondary antisera and developed with aminoethylcarbazole as a chromogen. A differentiated localized staining pattern of SUR proteins in rat and mouse ureters is demonstrated. In the mouse, immunoreactivity of SUR2A was predominantly confined to the cytoplasmic portion of epithelial cells and blood vessels, with comparatively low-level staining found in smooth muscle. In contrast, SUR2B (SUR1) immunoreactivity was absent in mouse ureters. In rats, SUR2A immunoreactivity was localized only in the blood vessels, while SUR2B (SUR1) immunoreactivity was localized in the epithelial cell cytoplasm. Tissue specificity of SUR is demonstrated in the two species of rodents and suggests a role of SUR proteins in urinary metabolism pertaining possibly to salt handling and maintenance of the smooth muscle tone.
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Affiliation(s)
- I Z Qureshi
- Department of Biomedical Science, Sheffield University, Western Bank Sheffield, Sheffield, S10 2TN, UK.
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Cantsilieris S, White SJ, Richardson AJ, Guymer RH, Baird PN. Comprehensive analysis of Copy Number Variation of genes at chromosome 1 and 10 loci associated with late age related macular degeneration. PLoS One 2012; 7:e35255. [PMID: 22558131 PMCID: PMC3338825 DOI: 10.1371/journal.pone.0035255] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 03/14/2012] [Indexed: 11/18/2022] Open
Abstract
Copy Number Variants (CNVs) are now recognized as playing a significant role in complex disease etiology. Age-related macular degeneration (AMD) is the most common cause of irreversible vision loss in the western world. While a number of genes and environmental factors have been associated with both risk and protection in AMD, the role of CNVs has remained largely unexplored. We analyzed the two major AMD risk-associated regions on chromosome 1q32 and 10q26 for CNVs using Multiplex Ligation-dependant Probe Amplification. The analysis targeted nine genes in these two key regions, including the Complement Factor H (CFH) gene, the 5 CFH-related (CFHR) genes representing a known copy number "hotspot", the F13B gene as well as the ARMS2 and HTRA1 genes in 387 cases of late AMD and 327 controls. No copy number variation was detected at the ARMS2 and HTRA1 genes in the chromosome 10 region, nor for the CFH and F13B genes at the chromosome 1 region. However, significant association was identified for the CFHR3-1 deletion in AMD cases (p = 2.38 × 10(-12)) OR = 0.31, CI-0.95 (0.23-0.44), for both neovascular disease (nAMD) (p = 8.3 × 10(-9)) OR = 0.36 CI-0.95 (0.25-0.52) and geographic atrophy (GA) (p = 1.5 × 10(-6)) OR = 0.36 CI-0.95 (0.25-0.52) compared to controls. In addition, a significant association with deletion of CFHR1-4 was identified only in patients who presented with bilateral GA (p = 0.02) (OR = 7.6 CI-0.95 1.38-41.8). This is the first report of a phenotype specific association of a CNV for a major subtype of AMD and potentially allows for pre-diagnostic identification of individuals most likely to proceed to this end stage of disease.
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Affiliation(s)
- Stuart Cantsilieris
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Centre for Reproduction and Development, Monash Institute of Medical Research, Melbourne, Victoria, Australia
| | - Stefan J. White
- Centre for Reproduction and Development, Monash Institute of Medical Research, Melbourne, Victoria, Australia
| | - Andrea J. Richardson
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
| | - Robyn H. Guymer
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
| | - Paul N. Baird
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
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Abstract
DNaseI-hypersensitive sites within chromatin are indicative of genomic loci with regulatory function. Several techniques have been described for analyzing these regions, but are either laborious, offer low-throughput possibilities, or are expensive. We have developed a new approach based on a modified version of multiplex ligation-dependent probe amplification (MLPA). Using this method, it is possible to analyse up to 50 defined genomic regions for DNaseI-hypersensitivity in a single PCR-based reaction. This chapter outlines the approach and discusses the critical features of each step of the procedure.
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Affiliation(s)
- Thomas Ohnesorg
- Molecular Development Laboratory, Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia
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de Boer CM, Eini R, Gillis AM, Stoop H, Looijenga LHJ, White SJ. DICER1 RNase IIIb domain mutations are infrequent in testicular germ cell tumours. BMC Res Notes 2012. [DOI: 10.1186/1756-0500-5-2101791285670510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Hersmus R, Stoop H, White SJ, Drop SLS, Oosterhuis JW, Incrocci L, Wolffenbuttel KP, Looijenga LHJ. Delayed Recognition of Disorders of Sex Development (DSD): A Missed Opportunity for Early Diagnosis of Malignant Germ Cell Tumors. Int J Endocrinol 2012; 2012:671209. [PMID: 22315593 PMCID: PMC3272341 DOI: 10.1155/2012/671209] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 09/27/2011] [Accepted: 10/13/2011] [Indexed: 01/09/2023] Open
Abstract
Disorders of sex development (DSD) are defined as a congenital condition in which development of chromosomal, gonadal or anatomical sex is atypical. DSD patients with gonadal dysgenesis or hypovirilization, containing part of the Y chromosome (GBY), have an increased risk for malignant type II germ cell tumors (GCTs: seminomas and nonseminomas). DSD may be diagnosed in newborns (e.g., ambiguous genitalia), or later in life, even at or after puberty. Here we describe three independent male patients with a GCT; two were retrospectively recognized as DSD, based on the histological identification of both carcinoma in situ and gonadoblastoma in a single gonad as the cancer precursor. Hypospadias and cryptorchidism in their history are consistent with this conclusion. The power of recognition of these parameters is demonstrated by the third patient, in which the precursor lesion was diagnosed before progression to invasiveness. Early recognition based on these clinical parameters could have prevented development of (metastatic) cancer, to be treated by systemic therapy. All three patients showed a normal male 46,XY karyotype, without obvious genetic rearrangements by high-resolution whole-genome copy number analysis. These cases demonstrate overlap between DSD and the so-called testicular dysgenesis syndrome (TDS), of significant relevance for identification of individuals at increased risk for development of a malignant GCT.
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Affiliation(s)
- Remko Hersmus
- Department of Pathology, Erasmus MC-University Medical Center Rotterdam, Josephine Nefkens Institute, Daniel den Hoed Cancer Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Hans Stoop
- Department of Pathology, Erasmus MC-University Medical Center Rotterdam, Josephine Nefkens Institute, Daniel den Hoed Cancer Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Stefan J. White
- Centre for Reproduction and Development, Monash Institute of Medical Research, Melbourne, VIC, Australia
| | - Stenvert L. S. Drop
- Department of Pediatric Endocrinology, Erasmus MC-University Medical Center Rotterdam, Sophia, Rotterdam, The Netherlands
| | - J. Wolter Oosterhuis
- Department of Pathology, Erasmus MC-University Medical Center Rotterdam, Josephine Nefkens Institute, Daniel den Hoed Cancer Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Luca Incrocci
- Department of Radiation Oncology, Erasmus MC-University Medical Center Rotterdam, Daniel den Hoed Cancer Center, Rotterdam, The Netherlands
| | - Katja P. Wolffenbuttel
- Department of Pediatric Urology, Erasmus MC-University Medical Center Rotterdam, Sophia, Rotterdam, The Netherlands
| | - Leendert H. J. Looijenga
- Department of Pathology, Erasmus MC-University Medical Center Rotterdam, Josephine Nefkens Institute, Daniel den Hoed Cancer Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
- *Leendert H. J. Looijenga:
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Geddes A, Savin J, White SJ, Gibson J. Primary cutaneous cd8-positive t-cell lymphoma: a case report of a rare and aggressive disease with oral presentation. ACTA ACUST UNITED AC 2011; 38:472-4, 476. [DOI: 10.12968/denu.2011.38.7.472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- A Geddes
- SHO in Oral and Maxillofacial Surgery, Ninewells Hospital Dundee
| | - J Savin
- Surgical Specialist, Community Dental Services, NHS Fife
| | - SJ White
- Clinical Lecturer/Honorary Specialist Registrar in Pathology, Ninewells Hospital Dundee
| | - J Gibson
- Consultant and Honorary Senior Lecturer in Oral Medicine
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Neal AM, Taylor HC, Millar ID, Kibble JD, White SJ, Robson L. Renal defects in KCNE1 knockout mice are mimicked by chromanol 293B in vivo: identification of a KCNE1-regulated K+ conductance in the proximal tubule. J Physiol 2011; 589:3595-609. [PMID: 21576273 PMCID: PMC3167120 DOI: 10.1113/jphysiol.2011.209155] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Non-technical summary The kidney plays a critical role in regulating body fluid volume and blood pressure by conserving ions, solutes and water. Knowing the processes that underpin the handling of ions, solutes and water by the kidney is essential to our understanding of fluid and blood pressure regulation. Movement of ions is mediated by specific transport proteins found in the membranes of kidney cells. These proteins are regulated by additional proteins, called accessory proteins. In the current study, we have examined the role of the accessory protein KCNE1 in regulating a channel, KCNQ1, which is important in kidney function. We have observed that in the absence of KCNE1 the kidney has difficulty conserving sodium, chloride and water. However, by using specific inhibitors of these proteins we have also determined that although KCNE1 has a role in kidney function, the mechanism of its action is unlikely to be by regulating the protein KCNQ1. Abstract KCNE1 is a protein of low molecular mass that is known to regulate the chromanol 293B and clofilium-sensitive K+ channel, KCNQ1, in a number of tissues. Previous work on the kidney of KCNE1 and KCNQ1 knockout mice has revealed that these animals have different renal phenotypes, suggesting that KCNE1 may not regulate KCNQ1 in the renal system. In the current study, in vivo clearance approaches and whole cell voltage-clamp recordings from isolated renal proximal tubules were used to examine the physiological role of KCNE1. Data from wild-type mice were compared to those from KCNE1 knockout mice. In clearance studies the KCNE1 knockout mice had an increased fractional excretion of Na+, Cl−, HCO3− and water. This profile was mimicked in wild-type mice by infusion of chromanol 293B, while chromanol was without effect in KCNE1 knockout animals. Clofilium also increased the fractional excretion of Na+, Cl− and water, but this was observed in both wild-type and knockout mice, suggesting that KCNE1 was regulating a chromanol-sensitive but clofilium-insensitive pathway. In whole cell voltage clamp recordings from proximal tubules, a chromanol-sensitive, K+-selective conductance was identified that was absent in tubules from knockout animals. The properties of this conductance were not consistent with its being mediated by KCNQ1, suggesting that KCNE1 regulates another K+ channel in the renal proximal tubule. Taken together these data suggest that KCNE1 regulates a K+-selective conductance in the renal proximal tubule that plays a relatively minor role in driving the transport of Na+, Cl− and HCO3−.
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Affiliation(s)
- A M Neal
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, UK
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Abstract
Multiplex Ligation-dependent Probe Amplification (MLPA) is a PCR-based technique that was developed for identifying deletions and duplications in genomic DNA. The simplicity and sensitivity of this approach has led to it being implemented in many laboratories around the world. Since the original publication, there have been several variants of MLPA described, allowing the quantitative analysis of mRNA transcript levels, CpG methylation, complex genomic regions, and DNaseI hypersensitive sites. This chapter outlines the basic MLPA protocol, describes the different modifications and applications that have been published, and discusses the critical points during each of the steps.
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Affiliation(s)
- Thomas Ohnesorg
- Molecular Development, Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia
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Bradley HJ, Liu X, Collins V, Owide J, Goli GR, Smith M, Surprenant A, White SJ, Jiang LH. Identification of an intracellular microdomain of the P2X7 receptor that is crucial in basolateral membrane targeting in epithelial cells. FEBS Lett 2010; 584:4740-4. [PMID: 21073871 DOI: 10.1016/j.febslet.2010.11.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 10/29/2010] [Accepted: 11/05/2010] [Indexed: 10/18/2022]
Abstract
We investigated membrane targeting of the P2X(7) receptor (P2X(7)R) in polarized epithelial cells using immunofluorescent confocal imaging. The wild-type receptor was targeted to the basolateral membrane, independently of adaptor protein μ1B. Deletion of the majority of the intracellular C-terminus, or the last 26 residues (P570-Y595), conferred targeting of the protein to the apical membrane. Alanine substitution in the microdomain P582-Q587 caused similar apical membrane targeting without major effect on the receptor function and surface expression. Our results show basolateral membrane targeting of the P2X(7)R in epithelial cells and that the intracellular C-terminal microdomain P582-Q587 is crucial in this process.
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Affiliation(s)
- H J Bradley
- Faculty of Biological Sciences, University of Leeds, Leeds, UK
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Ohnesorg T, Eggers S, Leonhard WN, Sinclair AH, White SJ. Rapid high-throughput analysis of DNaseI hypersensitive sites using a modified Multiplex Ligation-dependent Probe Amplification approach. BMC Genomics 2009; 10:412. [PMID: 19728890 PMCID: PMC2748097 DOI: 10.1186/1471-2164-10-412] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 09/04/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mapping DNaseI hypersensitive sites is commonly used to identify regulatory regions in the genome. However, currently available methods are either time consuming and laborious, expensive or require large numbers of cells. We aimed to develop a quick and straightforward method for the analysis of DNaseI hypersensitive sites that overcomes these problems. RESULTS We have developed a modified Multiplex Ligation-dependent Probe Amplification (MLPA) approach for the identification and analysis of genomic regulatory regions. The utility of this approach was demonstrated by simultaneously analysing 20 loci from the ENCODE project for DNaseI hypersensitivity in a range of different cell lines. We were able to obtain reproducible results with as little as 5 x 10(4) cells per DNaseI treatment. Our results broadly matched those previously reported by the ENCODE project, and both technical and biological replicates showed high correlations, indicating the sensitivity and reproducibility of this method. CONCLUSION This new method will considerably facilitate the identification and analysis of DNaseI hypersensitive sites. Due to the multiplexing potential of MLPA (up to 50 loci can be examined) it is possible to analyse dozens of DNaseI hypersensitive sites in a single reaction. Furthermore, the high sensitivity of MLPA means that fewer than 10(5) cells per DNaseI treatment can be used, allowing the discovery and analysis of tissue specific regulatory regions without the need for pooling. This method is quick and easy and results can be obtained within 48 hours after harvesting of cells or tissues. As no special equipment is required, this method can be applied by any laboratory interested in the analysis of DNaseI hypersensitive regions.
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Affiliation(s)
- Thomas Ohnesorg
- Murdoch Children's Research Institute and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, VIC, Australia
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Notini AJ, Li R, Western PS, Sinclair AH, White SJ. Rapid and reliable determination of transgene zygosity in mice by multiplex ligation-dependent probe amplification. Transgenic Res 2009; 18:987-91. [PMID: 19504348 DOI: 10.1007/s11248-009-9284-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Accepted: 05/14/2009] [Indexed: 11/30/2022]
Abstract
The ability to rapidly and unequivocally distinguish heterozygous from homozygous transgenic mice is an integral part of any breeding strategy. Here we describe a quick and simple protocol for determining the zygosity of transgenic mice at multiple loci in a single reaction. This involved the development of a multiplex ligation-dependent probe amplification (MLPA) probe mix to simultaneously measure common transgenic alleles such as Cre recombinase (Cre), neomycin (Neo), beta-galactosidase (LacZ) and enhanced green fluorescent protein (eGFP), as well as loci specific to the X and Y chromosome to allow sexing. Each reaction required as little as 100 ng of genomic DNA isolated from a tail biopsy using a simple procedure. Normalization against autosomal control loci resulted in 100% call accuracy, with no ambiguous results. This probe mix can be easily implemented in any laboratory with access to a PCR machine and a DNA sequencer, and can be rapidly adapted to genotype any additional loci of interest.
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Affiliation(s)
- Amanda J Notini
- Murdoch Children's Research Institute and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, VIC, Australia.
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Cobb JE, White SJ, Harrap SB, Ellis JA. Androgen receptor copy number variation and androgenetic alopecia: a case-control study. PLoS One 2009; 4:e5081. [PMID: 19340294 PMCID: PMC2659771 DOI: 10.1371/journal.pone.0005081] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Accepted: 03/06/2009] [Indexed: 11/18/2022] Open
Abstract
Background The functional polymorphism that explains the established association of the androgen receptor (AR) with androgenetic alopecia (AGA) remains unidentified, but Copy Number Variation (CNV) might be relevant. CNV involves changes in copy number of large segments of DNA, leading to the altered dosage of gene regulators or genes themselves. Two recent reports indicate regions of CNV in and around AR, and these have not been studied in relation to AGA. The aim of this preliminary case-control study was to determine if AR CNV is associated with AGA, with the hypothesis that CNV is the functional AR variant contributing to this condition. Methodology/Principal Findings Multiplex Ligation-dependent Probe Amplification was used to screen for CNV in five AR exons and a conserved, non-coding region upstream of AR in 85 men carefully selected as cases and controls for maximal phenotypic contrast. There was no evidence of CNV in AR in any of the cases or controls, and thus no evidence of significant association between AGA and AR CNV. Conclusions/Significance The results suggest this form of genomic variation at the AR locus is unlikely to predispose to AGA.
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Affiliation(s)
- Joanna E. Cobb
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Stefan J. White
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Stephen B. Harrap
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Justine A. Ellis
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- * E-mail:
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Abstract
Mosaicism is the presence of cells within an organism that have a different genetic composition despite deriving from a single zygote. The consequence of this depends on the number and type of cells that are affected as well as the specific DNA involved. There are several diseases where mosaicism is known to occur, but the currently observed frequency is presumably an underestimation due to the difficulty of detecting changes in only a percentage of cells. Recent advances in technology have provided a greater insight into the frequency and mechanisms of mosaicism in all forms. This review will cover the different techniques that can be used for detecting copy number variation (CNV) in mosaic form, and describe some of the insights that different diseases have given on the true frequencies and mechanisms responsible for somatic rearrangements. It will conclude with a discussion of the implications of the recent description of CNV in identical twins, and what remains to be elucidated in the world of mosaic CNV.
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Affiliation(s)
- A J Notini
- Molecular Development, Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Vic. Australia
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41
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Thabet MM, Huizinga TWJ, Marques RB, Stoeken-Rijsbergen G, Bakker AM, Kurreeman FA, White SJ, Toes REM, van der Helm-van Mil AHM. Contribution of Fc receptor IIIA gene 158V/F polymorphism and copy number variation to the risk of ACPA-positive rheumatoid arthritis. Ann Rheum Dis 2008; 68:1775-80. [DOI: 10.1136/ard.2008.099309] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abstract
The detection of quantitative changes in genomic DNA, i.e., deletions and duplications or so called Copy Number Variants (CNV), is an important element of a complete mutation screening strategy. However, because of practical difficulties, screening for quantitative changes in genomic DNA is often ignored. Hitherto, the techniques available were technically challenging and laborious and thus too costly to be applied on a routine basis. The development of MAPH (Multiplex Amplifiable Probe Hybridization) and more recently MLPA (Multiplex Ligation-dependent Probe Amplification) have revived interest in the detection of deletions and duplications, primarily due to the simplicity and flexibility of these two approaches. Compared to previous technologies, e.g., Southern blotting, fluorescence in situ hybridization (FISH), quantitative PCR (qPCR), and breakpoint PCR, they have some clear advantages, including high resolution, high throughput, amenability to multiplexing, and simplicity.
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Affiliation(s)
- Johan T den Dunnen
- Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
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Walenkamp MJE, de Muinck Keizer-Schrama SMPF, de Mos M, Kalf ME, van Duyvenvoorde HA, Boot AM, Kant SG, White SJ, Losekoot M, Den Dunnen JT, Karperien M, Wit JM. Successful long-term growth hormone therapy in a girl with haploinsufficiency of the insulin-like growth factor-I receptor due to a terminal 15q26.2->qter deletion detected by multiplex ligation probe amplification. J Clin Endocrinol Metab 2008; 93:2421-5. [PMID: 18349070 DOI: 10.1210/jc.2007-1789] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Microscopically visible heterozygous terminal 15q deletions encompassing the IGF1R gene are rare and usually associated with intrauterine growth retardation and short stature. The incidence of submicroscopic deletions is unknown, as is the effect of GH therapy in this condition. OBJECTIVE The objective of the study was to describe the use of a novel genetic technique [multiplex ligation probe amplification (MLPA)] to detect haploinsufficiency of the IGF1R gene in a patient suspected of an IGF1R gene defect and evaluate the effect of long-term GH therapy. PATIENT A 15-yr-old adolescent, born small for gestational age, showed persistent postnatal growth retardation, microcephaly, and elevated IGF-I levels. She had been treated with GH since the age of 5 yr. METHODS MLPA and array comparative genomic hybridization (aCGH) were performed to examine gene copy number changes. Dermal fibroblast cultures were used for functional analysis. RESULTS With MLPA, a deletion of one copy of the IGF1R gene was detected, defined by aCGH as a loss of 15q26.2->qter. IGF1R mRNA expression was decreased in fibroblasts. IGF-I binding and type 1 IGF receptor protein expression as well as activation of type 1 IGF receptor autophosphorylation and protein kinase B/Akt by IGF-I tended to be lower, but this did not reach statistical significance. GH treatment resulted in a good growth response and a normal adult height. CONCLUSIONS MLPA and aCGH are useful tools to detect submicroscopic deletions of the IGF1R gene in patients born small for gestational age with persistent growth failure. The phenotype resembles that of a heterozygous inactivating IGF1R mutation. Long-term GH therapy causes growth acceleration in childhood and a normal adult height.
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Affiliation(s)
- Marie J E Walenkamp
- Department of Pediatrics J6-S, Leiden University Medical Center, Leiden, The Netherlands.
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White SJ, Vissers LELM, Geurts van Kessel A, de Menezes RX, Kalay E, Lehesjoki AE, Giordano PC, van de Vosse E, Breuning MH, Brunner HG, den Dunnen JT, Veltman JA. Variation of CNV distribution in five different ethnic populations. Cytogenet Genome Res 2007; 118:19-30. [PMID: 17901696 DOI: 10.1159/000106437] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Accepted: 03/12/2007] [Indexed: 12/12/2022] Open
Abstract
Recent studies have revealed a new type of variation in the human genome encompassing relatively large genomic segments ( approximately 100 kb-2.5 Mb), commonly referred to as copy number variation (CNV). The full nature and extent of CNV and its frequency in different ethnic populations is still largely unknown. In this study we surveyed a set of 12 CNVs previously detected by array-CGH. More than 300 individuals from five different ethnic populations, including three distinct European, one Asian and one African population, were tested for the occurrence of CNV using multiplex ligation-dependent probe amplification (MLPA). Seven of these loci indeed showed CNV, i.e., showed copy numbers that deviated from the population median. More precise estimations of the actual genomic copy numbers for (part of) the NSF gene locus, revealed copy numbers ranging from two to at least seven. Additionally, significant inter-population differences in the distribution of these copy numbers were observed. These data suggest that insight into absolute DNA copy numbers for loci exhibiting CNV is required to determine their potential contribution to normal phenotypic variation and, in addition, disease susceptibility.
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Affiliation(s)
- S J White
- Center for Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
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Abstract
The chicken has long been an important model organism for developmental biology, as well as a major source of protein with billions of birds used in meat and egg production each year. Chicken genomics has been transformed in recent years, with the characterisation of large EST collections and most recently with the assembly of the chicken genome sequence. As the first livestock genome to be fully sequenced it leads the way for others to follow--with zebra finch later this year. The genome sequence and the availability of three million genetic polymorphisms are expected to aid the identification of genes that control traits of importance in poultry. As the first bird genome to be sequenced it is a model for the remaining 9,600 species thought to exist today. Many of the features of avian biology and organisation of the chicken genome make it an ideal model organism for phylogenetics and embryology, along with applications in agriculture and medicine. The availability of new tools such as whole-genome gene expression arrays and SNP panels, coupled with information resources on the genes and proteins are likely to enhance this position.
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Affiliation(s)
- D W Burt
- Department of Genomics and Genetics, Roslin Institute (Edinburgh), Roslin, Midlothian, UK.
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Harteveld CL, Kriek M, Bijlsma EK, Erjavec Z, Balak D, Phylipsen M, Voskamp A, di Capua E, White SJ, Giordano PC. Refinement of the genetic cause of ATR-16. Hum Genet 2007; 122:283-92. [PMID: 17598130 DOI: 10.1007/s00439-007-0399-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Accepted: 06/15/2007] [Indexed: 10/23/2022]
Abstract
Alpha thalassemia retardation associated with chromosome16 (ATR-16 syndrome) is defined as a contiguous gene syndrome resulting from haploinsufficiency of the alpha-globin gene cluster and genes involved in mental retardation (MR). To date, only few cases have been described which result from pure monosomy for a deletion of 16p. In most of these cases the deletion was identified by densitometric analysis of Southern blot results or by Fluorescent In Situ Hybridization analysis, and these alterations have not been mapped in detail. In this study, we have fine mapped deletions causing alpha-thalassemia within 2 Mb from the telomere of 16p by multiplex ligation-dependent probe amplification (MLPA). We have developed a rapid and simple test for high resolution mapping of rearrangements involving the tip of the short arm of chromosome 16 by incorporating 62 MLPA probes spaced approximately 10-200 kb over a region of 2 Mb from the telomere. One deletion of approximately 900 kb without MR was identified in addition to three de novo deletions varying between 1.5 and 2 Mb causing ATR-16 in three patients having mild MR and alpha-thalassemia. Two were found by chance to be ATR-16 because they were included in a study to search for telomeric loss in MR and not by hematological analysis. This would plead for more alertness when a persistent microcytic hypochromic anemia at normal ferritin levels is observed as suggestive for the ATR-16 syndrome. The region on chromosome 16p for which haploinsufficiency leads to the dysmorphic features and MR typical for ATR-16, has been narrowed down to a 800 kb region localized between 0.9 and 1.7 Mb from the telomere.
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Affiliation(s)
- Cornelis L Harteveld
- Department of Clinical Genetics, Center of Human and Clinical Genetics, Leiden University Medical Center (LUMC), 2333RC Leiden, The Netherlands.
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van Tintelen JP, Tio RA, Kerstjens-Frederikse WS, van Berlo JH, Boven LG, Suurmeijer AJH, White SJ, den Dunnen JT, te Meerman GJ, Vos YJ, van der Hout AH, Osinga J, van den Berg MP, van Veldhuisen DJ, Buys CHCM, Hofstra RMW, Pinto YM. Severe Myocardial Fibrosis Caused by a Deletion of the 5’ End of the Lamin A/C Gene. J Am Coll Cardiol 2007; 49:2430-9. [PMID: 17599607 DOI: 10.1016/j.jacc.2007.02.063] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Revised: 02/09/2007] [Accepted: 02/12/2007] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The goal of this study was to identify the underlying gene defect in a family with inherited myocardial fibrosis. BACKGROUND A large family with an autosomal dominantly inherited form of myocardial fibrosis with a highly malignant clinical outcome has been investigated. Because myocardial fibrosis preceded the clinical and echocardiographic signs, we consider the disease to be a hereditary form of cardiac fibrosis. METHODS Twenty-five family members were clinically evaluated, and 5 unaffected and 8 affected family members were included in a genome-wide linkage study. RESULTS The highest logarithm of the odds (LOD) score (LOD = 2.6) was found in the region of the lamin AC (LMNA) gene. The LMNA mutation analysis, both by denaturing gradient gel electrophoresis and sequencing, failed to show a mutation. Subsequent Southern blotting, complementary deoxyribonucleic acid sequencing, and multiplex ligation-dependent probe amplification analysis, however, revealed a deletion of the start codon-containing exon and an adjacent noncoding exon. In vitro studies demonstrated that the deletion results in the formation of nuclear aggregates of lamin, suggesting that the mutant allele is being transcribed. CONCLUSIONS This novel LMNA deletion causes a distinct, highly malignant cardiomyopathy with early-onset primary cardiac fibrosis likely due to an effect of the shortened mutant protein, which secondarily leads to arrhythmias and end-stage cardiac failure.
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Affiliation(s)
- J Peter van Tintelen
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
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Kriek M, Knijnenburg J, White SJ, Rosenberg C, den Dunnen JT, van Ommen GJB, Tanke HJ, Breuning MH, Szuhai K. Diagnosis of genetic abnormalities in developmentally delayed patients: a new strategy combining MLPA and array-CGH. Am J Med Genet A 2007; 143A:610-4. [PMID: 17318845 DOI: 10.1002/ajmg.a.31593] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marjolein Kriek
- Center for Human and Clinical Genetics, Leiden University Medical Center, RC Leiden, The Netherlands.
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Hameetman L, David G, Yavas A, White SJ, Taminiau AHM, Cleton-Jansen AM, Hogendoorn PCW, Bovée JVMG. Decreased EXT expression and intracellular accumulation of heparan sulphate proteoglycan in osteochondromas and peripheral chondrosarcomas. J Pathol 2007; 211:399-409. [PMID: 17226760 DOI: 10.1002/path.2127] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mutational inactivation of EXT1 or EXT2 is the cause of hereditary multiple osteochondromas. These genes function in heparan sulphate proteoglycan (HSPG) biosynthesis in the Golgi apparatus. Loss of heterozygosity of the EXT1 locus at 8q24 is frequently found in solitary osteochondromas, whereas somatic mutations are rarely found. We investigated the expression of EXT1 and EXT2 (quantitative RT-PCR) and of different HSPGs (immunohistochemistry) in solitary and hereditary osteochondromas and in cases with malignant progression to secondary peripheral chondrosarcoma, in relation to possible mutations and promoter methylation. The mutation status of patients with multiple osteochondromas correlated with decreased EXT1 or EXT2 expression found in their resected tumours. We could not show somatic point mutations or promoter hypermethylation in 17 solitary tumours; however, EXT1 expression was decreased in 15 cases, whereas EXT2 was not. Intracellular accumulation of syndecan-2 and heparan sulphate-bearing isoforms of CD44 (CD44v3) was found in most tumours, which concentrated in the Golgi apparatus as shown by confocal microscopy. This contrasted with the extracellular expression found in normal growth plates. In conclusion, mutational inactivation of either EXT1 or EXT2 leads to loss of mRNA expression of the corresponding gene. We hypothesize that loss of EXT expression disrupts the function of the EXT1/2 complex in HSPG biosynthesis, resulting in the intracellular accumulation of HSPG core proteins that we found in these tumours.
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Affiliation(s)
- L Hameetman
- Department of Pathology, Leiden University Medical Centre, Leiden, The Netherlands
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White SJ, den Dunnen JT. Copy number variation in the genome; the human DMD gene as an example. Cytogenet Genome Res 2006; 115:240-6. [PMID: 17124406 DOI: 10.1159/000095920] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Accepted: 05/15/2006] [Indexed: 11/19/2022] Open
Abstract
Recent developments have yielded new technologies that have greatly simplified the detection of deletions and duplications, i.e., copy number variants (CNVs). These technologies can be used to screen for CNVs in and around specific genomic regions, as well as genome-wide. Several genome-wide studies have demonstrated that CNV in the human genome is widespread and may include millions of nucleotides. One of the questions that emerge is which sequences, structures and/or processes are involved in their generation. Using as an example the human DMD gene, mutations in which cause Duchenne and Becker muscular dystrophy, we review the current data, determine the deletion and duplication profile across the gene and summarize the information that has been collected regarding their origin. In addition we discuss the methods most frequently used for their detection, in particular MAPH and MLPA.
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Affiliation(s)
- S J White
- Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
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