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Laboratory testing for fragile X, 2021 revision: a technical standard of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2021; 23:799-812. [PMID: 33795824 DOI: 10.1038/s41436-021-01115-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 11/08/2022] Open
Abstract
Molecular genetic testing of the FMR1 gene is commonly performed in clinical laboratories. Pathogenic variants in the FMR1 gene are associated with fragile X syndrome, fragile X-associated tremor ataxia syndrome (FXTAS), and fragile X-associated primary ovarian insufficiency (FXPOI). This document provides updated information regarding FMR1 pathogenic variants, including prevalence, genotype-phenotype correlations, and variant nomenclature. Methodological considerations are provided for Southern blot analysis and polymerase chain reaction (PCR) amplification of FMR1, including triplet repeat-primed and methylation-specific PCR.The American College of Medical Genetics and Genomics (ACMG) Laboratory Quality Assurance Committee has the mission of maintaining high technical standards for the performance and interpretation of genetic tests. In part, this is accomplished by the publication of the document ACMG Technical Standards for Clinical Genetics Laboratories, which is now maintained online ( http://www.acmg.net ). This subcommittee also reviews the outcome of national proficiency testing in the genetics area and may choose to focus on specific diseases or methodologies in response to those results. Accordingly, the subcommittee selected fragile X syndrome to be the first topic in a series of supplemental sections, recognizing that it is one of the most frequently ordered genetic tests and that it has many alternative methods with different strengths and weaknesses. This document is the fourth update to the original standards and guidelines for fragile X testing that were published in 2001, with revisions in 2005 and 2013, respectively.This versionClarifies the clinical features associated with different FMRI variants (Section 2.3)Discusses important reporting considerations (Section 3.3.1.3)Provides updates on technology (Section 4.1).
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Hayward BE, Kumari D, Usdin K. Recent advances in assays for the fragile X-related disorders. Hum Genet 2017; 136:1313-1327. [PMID: 28866801 DOI: 10.1007/s00439-017-1840-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 08/24/2017] [Indexed: 12/17/2022]
Abstract
The fragile X-related disorders are a group of three clinical conditions resulting from the instability of a CGG-repeat tract at the 5' end of the FMR1 transcript. Fragile X-associated tremor/ataxia syndrome (FXTAS) and fragile X-associated primary ovarian insufficiency (FXPOI) are disorders seen in carriers of FMR1 alleles with 55-200 repeats. Female carriers of these premutation (PM) alleles are also at risk of having a child who has an FMR1 allele with >200 repeats. Most of these full mutation (FM) alleles are epigenetically silenced resulting in a deficit of the FMR1 gene product, FMRP. This results in fragile X Syndrome (FXS), the most common heritable cause of intellectual disability and autism. The diagnosis and study of these disorders is challenging, in part because the detection of alleles with large repeat numbers has, until recently, been either time-consuming or unreliable. This problem is compounded by the mosaicism for repeat length and/or DNA methylation that is frequently seen in PM and FM carriers. Furthermore, since AGG interruptions in the repeat tract affect the risk that a FM allele will be maternally transmitted, the ability to accurately detect these interruptions in female PM carriers is an additional challenge that must be met. This review will discuss some of the pros and cons of some recently described assays for these disorders, including those that detect FMRP levels directly, as well as emerging technologies that promise to improve the diagnosis of these conditions and to be useful in both basic and translational research settings.
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Affiliation(s)
- Bruce E Hayward
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, Building 8, Room 2A19, National Institutes of Health, 8 Center Drive MSC 0830, Bethesda, MD, 20892, USA
| | - Daman Kumari
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, Building 8, Room 2A19, National Institutes of Health, 8 Center Drive MSC 0830, Bethesda, MD, 20892, USA
| | - Karen Usdin
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, Building 8, Room 2A19, National Institutes of Health, 8 Center Drive MSC 0830, Bethesda, MD, 20892, USA.
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Hadd AG, Filipovic-Sadic S, Zhou L, Williams A, Latham GJ, Berry-Kravis E, Hall DA. A methylation PCR method determines FMR1 activation ratios and differentiates premutation allele mosaicism in carrier siblings. Clin Epigenetics 2016; 8:130. [PMID: 27980694 PMCID: PMC5131543 DOI: 10.1186/s13148-016-0280-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 10/23/2016] [Indexed: 01/02/2023] Open
Abstract
Background Epigenetic modifications of the fragile X mental retardation 1 (FMR1) gene locus may impact the risk for reproductive and neurological disorders associated with expanded trinucleotide repeats and methylation status in the 5′ untranslated region. FMR1 methylation is commonly assessed by Southern blot (SB) analysis, yet this method suffers a cumbersome workflow and relatively poor sizing resolution especially for premutation allele characteristic for fragile X-associated disorders. In this study, a methylation PCR (mPCR) assay was used to evaluate correlations among genotype, epitype, and phenotype in fragile X premutation (PM) carrier women in order to advance the understanding of the association between molecular determinants and the presence of fragile X-associated tremor and ataxia (FXTAS). Results Activation ratios (ARs) in 39 PM women were determined by mPCR and compared with SB analysis. ARs were distributed across a range of values including five samples with <20% AR and six with >80% AR. The two methods were correlated (R2 of 0.87 and F test of <0.001), indicating that mPCR can measure AR in agreement with established assays. However, mPCR was unique in identifying novel and distinct patterns of methylation mosaicism in premutation carrier women, including seven sibling pairs that were assessed using FXTAS clinical rating scales. Of note, four of six pairs with defined age of onset for neurological signs showed ARs consistent with skewed activation of the pathogenic expanded allele. One subject with severe FXTAS had a mosaic full mutation allele identified using mPCR but not detected by SB analysis. Conclusions We utilized a repeatable and streamlined methodology to characterize FMR1 inactivation in premutation carrier women. The method was concordant with SB analysis and provided higher resolution information on allele and methylation mosaicism. This approach can facilitate the characterization of epigenetic factors influencing fragile X phenotypes in larger cohort studies that can advance understanding and treatment of fragile X-associated disorders. Electronic supplementary material The online version of this article (doi:10.1186/s13148-016-0280-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Andrew G Hadd
- Research and Technology Development, Asuragen, Inc., Austin, TX 78744 USA
| | | | - Lili Zhou
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL USA ; Departments of Pediatrics and Biochemistry, Rush University Medical Center, Chicago, IL USA
| | - Arianna Williams
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL USA
| | - Gary J Latham
- Research and Technology Development, Asuragen, Inc., Austin, TX 78744 USA
| | - Elizabeth Berry-Kravis
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL USA ; Departments of Pediatrics and Biochemistry, Rush University Medical Center, Chicago, IL USA
| | - Deborah A Hall
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL USA
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Molecular Correlates and Recent Advancements in the Diagnosis and Screening of FMR1-Related Disorders. Genes (Basel) 2016; 7:genes7100087. [PMID: 27754417 PMCID: PMC5083926 DOI: 10.3390/genes7100087] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/06/2016] [Accepted: 10/08/2016] [Indexed: 12/12/2022] Open
Abstract
Fragile X syndrome (FXS) is the most common monogenic cause of intellectual disability and autism. Molecular diagnostic testing of FXS and related disorders (fragile X-associated primary ovarian insufficiency (FXPOI) and fragile X-associated tremor/ataxia syndrome (FXTAS)) relies on a combination of polymerase chain reaction (PCR) and Southern blot (SB) for the fragile X mental retardation 1 (FMR1) CGG-repeat expansion and methylation analyses. Recent advancements in PCR-based technologies have enabled the characterization of the complete spectrum of CGG-repeat mutation, with or without methylation assessment, and, as a result, have reduced our reliance on the labor- and time-intensive SB, which is the gold standard FXS diagnostic test. The newer and more robust triplet-primed PCR or TP-PCR assays allow the mapping of AGG interruptions and enable the predictive analysis of the risks of unstable CGG expansion during mother-to-child transmission. In this review, we have summarized the correlation between several molecular elements, including CGG-repeat size, methylation, mosaicism and skewed X-chromosome inactivation, and the extent of clinical involvement in patients with FMR1-related disorders, and reviewed key developments in PCR-based methodologies for the molecular diagnosis of FXS, FXTAS and FXPOI, and large-scale (CGG)n expansion screening in newborns, women of reproductive age and high-risk populations.
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Luchi N, Capretti P, Pazzagli M, Pinzani P. Powerful qPCR assays for the early detection of latent invaders: interdisciplinary approaches in clinical cancer research and plant pathology. Appl Microbiol Biotechnol 2016; 100:5189-204. [PMID: 27112348 DOI: 10.1007/s00253-016-7541-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 04/07/2016] [Accepted: 04/10/2016] [Indexed: 12/29/2022]
Abstract
Latent invaders represent the first step of disease before symptoms occur in the host. Based on recent findings, tumors are considered to be ecosystems in which cancer cells act as invasive species that interact with the native host cell species. Analogously, in plants latent fungal pathogens coevolve within symptomless host tissues. For these reasons, similar detection approaches can be used for an early diagnosis of the invasion process in both plants and humans to prevent or reduce the spread of the disease. Molecular tools based on the evaluation of nucleic acids have been developed for the specific, rapid, and early detection of human diseases. During the last decades, these techniques to assess and quantify the proliferation of latent invaders in host cells have been transferred from the medical field to different areas of scientific research, such as plant pathology. An improvement in molecular biology protocols (especially referring to qPCR assays) specifically designed and optimized for detection in host plants is therefore advisable. This work is a cross-disciplinary review discussing the use of a methodological approach that is employed within both medical and plant sciences. It provides an overview of the principal qPCR tools for the detection of latent invaders, focusing on comparisons between clinical cancer research and plant pathology, and recent advances in the early detection of latent invaders to improve prevention and control strategies.
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Affiliation(s)
- Nicola Luchi
- National Research Council (IPSP-CNR), Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019, Sesto Fiorentino Firenze, Italy
| | - Paolo Capretti
- National Research Council (IPSP-CNR), Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019, Sesto Fiorentino Firenze, Italy
- Department of Agri-Food Productions and Environmental Sciences (DiSPAA), University of Florence, Piazzale delle Cascine 28, Florence, Italy
| | - Mario Pazzagli
- Department of Clinical, Experimental and Biomedical Sciences, University of Florence, Viale Pieraccini, 6, 50139, Firenze, Italy
| | - Pamela Pinzani
- Department of Clinical, Experimental and Biomedical Sciences, University of Florence, Viale Pieraccini, 6, 50139, Firenze, Italy.
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Abstract
Fragile X syndrome (FXS), a trinucleotide repeat disorder, is the most common heritable form of cognitive impairment. Since the discovery of the FMR1 gene in 1991, great strides have been made in the field of molecular diagnosis for FXS. Cytogenetic analysis, which was the method of diagnosis in the early 1990, was replaced by Southern blot and PCR analysis albeit with some limitations. In the past few years many PCR-based methodologies, able to amplify large full mutation expanded alleles, with or without methylation, have been proposed. Reviewed here are the advantages, disadvantages and limitations of the most recent developments in the field of FXS diagnosis.
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Affiliation(s)
- Flora Tassone
- a Department of Biochemistry and Molecular Medicine , University of California, Davis, School of Medicine , Davis , CA 95616 , USA.,b MIND Institute , University of California Davis Medical Center , Sacramento , CA 95817 , USA
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Detection of skewed X-chromosome inactivation in Fragile X syndrome and X chromosome aneuploidy using quantitative melt analysis. Expert Rev Mol Med 2015; 17:e13. [PMID: 26132880 PMCID: PMC4836209 DOI: 10.1017/erm.2015.11] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Methylation of the fragile X mental retardation 1 (FMR1) exon 1/intron 1
boundary positioned fragile X related epigenetic element 2 (FREE2), reveals skewed
X-chromosome inactivation (XCI) in fragile X syndrome full mutation (FM: CGG > 200)
females. XCI skewing has been also linked to abnormal X-linked gene expression with the
broader clinical impact for sex chromosome aneuploidies (SCAs). In this study, 10 FREE2
CpG sites were targeted using methylation specific quantitative melt analysis (MS-QMA),
including 3 sites that could not be analysed with previously used EpiTYPER system. The
method was applied for detection of skewed XCI in FM females and in different types of
SCA. We tested venous blood and saliva DNA collected from 107 controls (CGG < 40),
and 148 FM and 90 SCA individuals. MS-QMA identified: (i) most SCAs if combined with a Y
chromosome test; (ii) locus-specific XCI skewing towards the hypomethylated state in FM
females; and (iii) skewed XCI towards the hypermethylated state in SCA with 3 or more X
chromosomes, and in 5% of the 47,XXY individuals. MS-QMA output also showed significant
correlation with the EpiTYPER reference method in FM males and females
(P < 0.0001) and SCAs (P < 0.05). In
conclusion, we demonstrate use of MS-QMA to quantify skewed XCI in two applications with
diagnostic utility.
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Tural S, Tekcan A, Kara N, Elbistan M, Güven D, Ali Tasdemir H. FMR1 gene mutation screening by TP-PCR in patients with premature ovarian failure and fragile-X. Gynecol Endocrinol 2015; 31:191-5. [PMID: 25366135 DOI: 10.3109/09513590.2014.975685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
CGG repeat expansion in the FMR1 gene is associated with fragile X syndrome, fragile X-associated tremor/ ataxia syndrome and fragile X-associated primary ovarian insufficiency. In this study, FMR1 gene mutation screening was carried out in 50 patients. Among them, 12 (%24) were POF and 19 (%38) were Fragile-X. We also examined the parents of the Fragile-X patients. DNA was extracted from blood with kit procedure. To examine expansion of the fragile-X CGG repeat, TP-PCR assay was performed and all amplicons were evaluated on an ABI3130XL Genetic Analyzer System by Fragman analysis. The data were analyzed by Gene Mapper Program. As a result of this study, the patients were identified with the fragile-X whose FMR1 gene CGG alleles have been observed in normal range. However, in patients who were referred with premature ovarian failure, pre-mutation frequency was observed as 6.6%. Only limited study in Turkish population reported frequency of pre-mutation carrier in POF and Fragile-X. Detection of pre-mutation carrier is important for next generation to have healthy siblings. We emphasize that TP-PCR technique is clear, reliable, sensitive, easy and fast method to detect pre-mutation. However, full mutations have to be examined by the technique of Southern blot in the diagnosis of fragile-X.
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Affiliation(s)
- Sengul Tural
- Faculy of Medicine, Department of Medical Biology, Section of Medical Genetics
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Hunter J, Rivero-Arias O, Angelov A, Kim E, Fotheringham I, Leal J. Epidemiology of fragile X syndrome: A systematic review and meta-analysis. Am J Med Genet A 2014; 164A:1648-58. [DOI: 10.1002/ajmg.a.36511] [Citation(s) in RCA: 238] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 01/31/2014] [Indexed: 12/18/2022]
Affiliation(s)
- Jessica Hunter
- Department of Human Genetics; Emory University School of Medicine; Atlanta Georgia
| | - Oliver Rivero-Arias
- Health Economics Research Centre; Nuffield Department of Population Health; University of Oxford; Oxford United Kingdom
- National Perinatal Epidemiology Unit; Nuffield Department of Population Health; University of Oxford; Oxford United Kingdom
| | - Angel Angelov
- Novartis Pharmaceutical Corporation; East Hanover New Jersey
| | - Edward Kim
- Novartis Pharmaceutical Corporation; East Hanover New Jersey
| | - Iain Fotheringham
- Value Demonstration Practice; Oxford PharmaGenesis™ Ltd; Oxford United Kingdom
| | - Jose Leal
- Health Economics Research Centre; Nuffield Department of Population Health; University of Oxford; Oxford United Kingdom
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Jorge P, Oliveira B, Marques I, Santos R. Development and validation of a multiplex-PCR assay for X-linked intellectual disability. BMC MEDICAL GENETICS 2013; 14:80. [PMID: 23914978 PMCID: PMC3751858 DOI: 10.1186/1471-2350-14-80] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 06/07/2013] [Indexed: 12/03/2022]
Abstract
Background X-linked intellectual disability is a common cause of inherited cognitive deficit affecting mostly males. There are several genetic causes implicated in this condition, which has hampered the establishment of an accurate diagnosis. We developed a multiplex-PCR assay for the mutational hotspot regions of the FMR1, AFF2 and ARX genes. Methods The multiplex-PCR was validated in a cohort of 100 males selected to include known alleles for the FMR1 repetitive region: five full mutations (250–650 CGGs), ten premutations (70–165 CGGs) and eighty-five in the normal range (19–42 CGGs). Sequencing or Southern blotting was used to confirm the results, depending on the allele class. In this cohort, with the exception of one sample showing an AFF2 intermediate-sized allele, all other samples were normal (8–34 CCGs). No ARX variant was found besides the c.429_452dup. The validated assay was applied to 5000 samples (64.4% males and 35.6% females). Results The normal-allelic range of both FMR1 and AFF2 genes as well as the nature of ARX variants identified was similar in both genders. The rate of homozygosity observed in female samples, 27.5% for FMR1 and 17.8% for AFF2 alleles, is comparable to that published by others. Two FMR1 premutations were identified, in a male (58 CGGs) and a female case [(CGG)47/(CGG)61], as well as several FMR1 or AFF2 intermediate-sized alleles. One AFF2 premutation (68 CCGs) and two putative full expansions were picked up in male subjects, which seems relevant considering the rarity of reported AFF2 mutations found in the absence of a family history. Conclusions We developed a robust multiplex-PCR that can be used to screen the mutational hotspot regions of FMR1, AFF2 and ARX genes. Moreover, this strategy led to the identification of variants in all three genes, representing not only an improvement in allele-sizing but also in achieving a differential diagnosis. Although the distinction between females who are truly homozygous and those with a second pre- or full mutation sized allele, as well as a definitive diagnosis, requires a specific downstream technique, the use of this multiplex-PCR for initial screening is a cost-effective approach which widens the scope of detection.
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Affiliation(s)
- Paula Jorge
- Centro de Genética Médica Dr, Jacinto Magalhães, CHP, Praça Pedro Nunes 88, 4099-028, Porto, Portugal.
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Monaghan KG, Lyon E, Spector EB. ACMG Standards and Guidelines for fragile X testing: a revision to the disease-specific supplements to the Standards and Guidelines for Clinical Genetics Laboratories of the American College of Medical Genetics and Genomics. Genet Med 2013; 15:575-86. [PMID: 23765048 DOI: 10.1038/gim.2013.61] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 04/04/2013] [Indexed: 12/29/2022] Open
Abstract
Molecular genetic testing of the FMR1 gene is commonly performed in clinical laboratories. Mutations in the FMR1 gene are associated with fragile X syndrome, fragile X tremor ataxia syndrome, and premature ovarian insufficiency. This document provides updated information regarding FMR1 gene mutations, including prevalence, genotype-phenotype correlation, and mutation nomenclature. Methodological considerations are provided for Southern blot analysis and polymerase chain reaction amplification of the FMR1 gene, including triplet repeat-primed and methylation-specific polymerase chain reaction. In addition to report elements, examples of laboratory reports for various genotypes are also included.
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Affiliation(s)
- Kristin G Monaghan
- Department of Medical Genetics, Henry Ford Health System, Detroit, Michigan, USA.
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Teo CRL, Law HY, Lee CG, Chong SS. Screening for CGG Repeat Expansion in the FMR1 Gene by Melting Curve Analysis of Combined 5′ and 3′ Direct Triplet-Primed PCRs. Clin Chem 2012; 58:568-79. [DOI: 10.1373/clinchem.2011.174615] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Abstract
BACKGROUND
CGG repeat expansions in the FMR1 (fragile X mental retardation 1) gene are associated with fragile X syndrome, fragile X–associated tremor/ataxia syndrome, and fragile X–associated primary ovarian insufficiency. We evaluated the use of melting curve analysis (MCA) of triplet-primed PCR (TP-PCR) assays as a rapid screening tool for the positive identification of expanded FMR1 alleles in men and women.
METHODS
Both 5′- and 3′-weighted direct TP-PCRs (dTP-PCRs) were evaluated on 29 cell line–derived DNA samples and 44 blinded clinical samples. The presence of expansions was identified by the melting curve profiles generated automatically through MCA on the LightCycler 480 Real-Time PCR System. All samples were also analyzed by capillary electrophoresis to confirm the identities of the PCR fragments that gave rise to the observed melt peak profiles.
RESULTS
The presence of expanded alleles in samples from both males and females produced melt peak profiles that were distinct from those of individuals with the normal allelic form. In the blinded test, positive and negative calls for the presence of an expanded allele corroborated with previously determined genotype classifications for all samples.
CONCLUSIONS
The approach of dTP-PCR plus MCA offers a single-step strategy with high diagnostic sensitivity and specificity for rapid screening detection of FMR1 CGG repeat expansions, regardless of sex. The combined use of 5′- and 3′-weighted dTP-PCR assays minimizes the incidence of false-negative results arising from repeat-flanking deletions.
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Affiliation(s)
- Clara R L Teo
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Hai-Yang Law
- Department of Pediatric Medicine, KK Women's and Children's Hospital, Singapore
| | - Caroline G Lee
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Division of Medical Sciences, National Cancer Center, Singapore
- Duke-NUS Graduate Medical School, Singapore
| | - Samuel S Chong
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- University Children's Medical Institute and
- Department of Laboratory Medicine, National University Hospital, Singapore
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Ai S, Shen L, Guo J, Feng X, Tang B. DNA Methylation as a Biomarker for Neuropsychiatric Diseases. Int J Neurosci 2012; 122:165-76. [DOI: 10.3109/00207454.2011.637654] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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