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Bolton PF, Clifford M, Tye C, Maclean C, Humphrey A, le Maréchal K, Higgins JNP, Neville BGR, Rijsdjik F, Yates JRW. Intellectual abilities in tuberous sclerosis complex: risk factors and correlates from the Tuberous Sclerosis 2000 Study. Psychol Med 2015; 45:2321-2331. [PMID: 25827976 DOI: 10.1017/s0033291715000264] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [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] [Indexed: 12/15/2022]
Abstract
BACKGROUND Tuberous sclerosis complex (TSC) is associated with intellectual disability, but the risk pathways are poorly understood. METHOD The Tuberous Sclerosis 2000 Study is a prospective longitudinal study of the natural history of TSC. One hundred and twenty-five UK children age 0-16 years with TSC and born between January 2001 and December 2006 were studied. Intelligence was assessed using standardized measures at ≥2 years of age. The age of onset of epilepsy, the type of seizure disorder, the frequency and duration of seizures, as well as the response to treatment was assessed at interview and by review of medical records. The severity of epilepsy in the early years was estimated using the E-Chess score. Genetic studies identified the mutations and the number of cortical tubers was determined from brain scans. RESULTS TSC2 mutations were associated with significantly higher cortical tuber count than TSC1 mutations. The extent of brain involvement, as indexed by cortical tuber count, was associated with an earlier age of onset and severity of epilepsy. In turn, the severity of epilepsy was strongly associated with the degree of intellectual impairment. Structural equation modelling supported a causal pathway from genetic abnormality to cortical tuber count to epilepsy severity to intellectual outcome. Infantile spasms and status epilepticus were important contributors to seizure severity. CONCLUSIONS The findings support the proposition that severe, early onset epilepsy may impair intellectual development in TSC and highlight the potential importance of early, prompt and effective treatment or prevention of epilepsy in tuberous sclerosis.
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Affiliation(s)
- P F Bolton
- MRC Centre for Social Genetic & Developmental Psychiatry & Department of Child Psychiatry,The Institute of Psychiatry,Kings College London,London,UK
| | - M Clifford
- MRC Centre for Social Genetic & Developmental Psychiatry & Department of Child Psychiatry,The Institute of Psychiatry,Kings College London,London,UK
| | - C Tye
- MRC Centre for Social Genetic & Developmental Psychiatry & Department of Child Psychiatry,The Institute of Psychiatry,Kings College London,London,UK
| | - C Maclean
- Department of Medical Genetics,University of Cambridge,Cambridge,UK
| | - A Humphrey
- Section of Developmental Psychiatry,University of Cambridge,Cambridge,UK
| | - K le Maréchal
- MRC Centre for Social Genetic & Developmental Psychiatry & Department of Child Psychiatry,The Institute of Psychiatry,Kings College London,London,UK
| | - J N P Higgins
- Department of Radiology,Addenbrooke's Hospital,Cambridge,UK
| | - B G R Neville
- Institute of Child Health,University College London UK and National Centre for Young People with Epilepsy,Lingfield,UK
| | - F Rijsdjik
- MRC Centre for Social Genetic & Developmental Psychiatry & Department of Child Psychiatry,The Institute of Psychiatry,Kings College London,London,UK
| | - J R W Yates
- Department of Medical Genetics,University of Cambridge,Cambridge,UK
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Khandhadia S, Cipriani V, Yates JRW, Lotery AJ. Age-related macular degeneration and the complement system. Immunobiology 2011; 217:127-46. [PMID: 21868123 DOI: 10.1016/j.imbio.2011.07.019] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2011] [Revised: 06/22/2011] [Accepted: 07/18/2011] [Indexed: 11/30/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world. It is a complex multifactorial disease, and despite new advances in treatment, many patients still succumb to visual impairment. The complement pathway has been implicated in the pathogenesis of many diseases, and recently variants in several genes encoding complement pathway proteins have been associated with AMD. Complement proteins have been found in histological specimens of eyes with AMD. Altered levels of both intrinsic complement proteins and activated products have been found in the circulation of patients with AMD. Complement activation may be triggered by oxidative stress, resulting from retinal exposure to incoming light; indeed an inter-play between these two pathological processes seems to exist. Finally, complement inhibitors are currently being evaluated in clinical trials. This article reviews the role of the complement system in AMD, and the potential of complement inhibition in preventing the devastating blindness resulting from this disease.
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Affiliation(s)
- S Khandhadia
- Clinical Neurosciences Division, University of Southampton, UK
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Kent L, Emerton J, Bhadravathi V, Weisblatt E, Pasco G, Willatt LR, McMahon R, Yates JRW. X-linked ichthyosis (steroid sulfatase deficiency) is associated with increased risk of attention deficit hyperactivity disorder, autism and social communication deficits. J Med Genet 2008; 45:519-24. [PMID: 18413370 DOI: 10.1136/jmg.2008.057729] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND X-linked ichthyosis (XLI) (steroid sulfatase deficiency) is caused by deletions or point mutations of the steroid sulfatase (STS) gene on chromosome Xp22.32. Deletions of this region can be associated with cognitive behavioural difficulties including autism. Animal work suggests the STS gene may be involved in attentional processes. We have therefore undertaken a systematic study of autism and attention deficit hyperactivity disorder (ADHD) in boys with XLI. METHODS Cases of XLI were recruited from families originally ascertained when pregnancies with STS deficiency were identified through a routine maternal screening programme. Boys with XLI were assessed for ADHD and autism using standardised questionnaires and interviews. Deletions of the STS gene were identified and characterised by analysis of genomic DNA and/or fluorescent in situ hybridisation. RESULTS 25 boys with XLI were assessed for autism and ADHD. 40% fulfilled DSM-IV criteria for a diagnosis of ADHD, 80% of which were inattentive subtype. ADHD diagnoses were present in those with both deletions and presumed point mutations of STS. Additionally, five boys, from three unrelated families, fulfilled criteria for an autistic spectrum disorder or related language/communication difficulty, and all had an unusually large deletion of the STS gene with loss of the neuroligin 4 (NLGN4) gene. None of the boys with the typical deletion or presumed point mutations of STS demonstrated autistic difficulties. CONCLUSIONS STS deficiency may be a risk factor for ADHD with predominantly inattentive symptoms. Boys with XLI and large deletions encompassing STS and NLGN4 are at increased risk of developing autism and related disorders.
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Affiliation(s)
- L Kent
- Bute Medical School, University of St Andrews, St Andrews KY169TS, UK.
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Pimenides D, George NDL, Yates JRW, Bradshaw K, Roberts SA, Moore AT, Trump D. X-linked retinoschisis: clinical phenotype and RS1 genotype in 86 UK patients. J Med Genet 2006; 42:e35. [PMID: 15937075 PMCID: PMC1736077 DOI: 10.1136/jmg.2004.029769] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Inactivating mutations of the gene RS1 lead to X-linked retinoschisis, a progressive retinal dystrophy characterised by schisis within the inner layers of the neuroretina. The mutation spectrum is large and the phenotype variable. AIM To determine whether there is a correlation between mutation type and disease severity. METHODS We identified the causative mutation in 86 affected patients and examined each of these patients in detail. Different categories of mutation were compared for each phenotypic characteristic. RESULTS We found a reduction in visual acuity with increasing age and worsening macular pathology in patients over 30 years old (p < or = 0.001), but there was no correlation between mutation type and severity of disease. Furthermore, we found a wide variation in phenotype even within families. CONCLUSIONS Identifying the causative mutation in patients with X-linked retinoschisis is helpful in confirming diagnosis and in counselling of family members but cannot be used to predict prognosis for an individual patient.
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Khan JC, Shahid H, Thurlby DA, Bradley M, Clayton DG, Moore AT, Bird AC, Yates JRW. Age related macular degeneration and sun exposure, iris colour, and skin sensitivity to sunlight. Br J Ophthalmol 2006; 90:29-32. [PMID: 16361662 PMCID: PMC1856929 DOI: 10.1136/bjo.2005.073825] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND/AIM It has been suggested that sun exposure may be a risk factor for age related macular degeneration (AMD) and that skin sensitivity to sunlight and iris colour could be confounding factors. The aim was to investigate this further in the white population. METHODS 446 cases with end stage AMD were compared with 283 spouse controls. Data on sun exposure, places of residence, iris colour, subjective assessment of change in iris colour, hair colour at age 20, and skin sensitivity were obtained using a questionnaire. Iris colour was graded clinically by comparison with standard photographs. AMD was graded using stereoscopic colour fundus photographs as well as clinical examination and was defined as the presence of geographic atrophy or choroidal neovascularisation. All variables were included in a multiple logistic regression model including age, sex, and smoking. RESULTS There was no association between AMD and sun exposure or related factors except for the suggestion of an association between sunburn prone skin type and geographic atrophy which reached borderline significance. CONCLUSIONS No significant association between AMD and sun exposure, iris colour, change in iris colour, or hair colour was demonstrated.
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Affiliation(s)
- J C Khan
- Department of Medical Genetics, University of Cambridge, Cambridge CB2 2QQ, UK
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Khan JC, Thurlby DA, Shahid H, Clayton DG, Yates JRW, Bradley M, Moore AT, Bird AC. Smoking and age related macular degeneration: the number of pack years of cigarette smoking is a major determinant of risk for both geographic atrophy and choroidal neovascularisation. Br J Ophthalmol 2006; 90:75-80. [PMID: 16361672 PMCID: PMC1856879 DOI: 10.1136/bjo.2005.073643] [Citation(s) in RCA: 240] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND/AIMS There is evidence that smoking is a risk factor for age related macular degeneration (AMD). However, not all studies have demonstrated this association and several key questions about the role of smoking in AMD have still to be determined. The aim of this study was to further investigate this relation for both choroidal neovascularisation (CNV) and geographic atrophy (GA). METHODS To investigate the relation between smoking and the risk of developing age related macular degeneration (AMD) in white people, 435 cases with end stage AMD were compared with 280 controls. All subjects had graded stereoscopic colour fundus photography and AMD was defined as the presence of GA or CNV. Smoking history was assessed using multiple parameters in a detailed questionnaire. RESULTS Comparison of current and former smokers with non-smokers was consistent with smoking being a risk factor for AMD but did not reach statistical significance. There was a strong association between AMD and pack years of cigarette smoking (p = 0.002), the odds ratio increasing with the amount smoked; for subjects with more than 40 pack years of smoking the odds ratio was 2.75 (95% CI 1.22 to 6.20) compared with non-smokers. Both types of AMD showed a similar relation; smoking more than 40 pack years of cigarettes was associated with an odds ratio of 3.43 (95% CI 1.28 to 9.20) for GA and 2.49 (95% CI 1.06 to 5.82) for CNV. Stopping smoking was associated with reduced odds of AMD and the risk in those who had not smoked for over 20 years was comparable to non-smokers. The risk profile was similar for males and females. Passive smoking exposure was associated with an increased risk of AMD (OR 1.87; 95% CI 1.03 to 3.40) in non-smokers. CONCLUSIONS The authors have demonstrated a strong association between the risk of both GA and CNV and pack years of cigarette smoking. This provides support for a causal relation between smoking and AMD. They also show an increased risk for AMD in non-smokers exposed to passive smoking. Stopping smoking appears to reduce the risk of developing AMD.
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Affiliation(s)
- J C Khan
- Department of Medical Genetics, University of Cambridge, Cambridge CB2 2QQ, UK
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Wang T, Waters CT, Jakins T, Yates JRW, Trump D, Bradshaw K, Moore AT. Temperature sensitive oculocutaneous albinism associated with missense changes in the tyrosinase gene. Br J Ophthalmol 2005; 89:1383-4. [PMID: 16170149 PMCID: PMC1772864 DOI: 10.1136/bjo.2005.070243] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Beysen D, Raes J, Leroy BP, Lucassen A, Yates JRW, Clayton-Smith J, Ilyina H, Brooks SS, Christin-Maitre S, Fellous M, Fryns JP, Kim JR, Lapunzina P, Lemyre E, Meire F, Messiaen LM, Oley C, Splitt M, Thomson J, Van de Peer Y, Veitia RA, De Paepe A, De Baere E. Deletions involving long-range conserved nongenic sequences upstream and downstream of FOXL2 as a novel disease-causing mechanism in blepharophimosis syndrome. Am J Hum Genet 2005; 77:205-18. [PMID: 15962237 PMCID: PMC1224524 DOI: 10.1086/432083] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [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: 04/22/2005] [Accepted: 05/19/2005] [Indexed: 11/03/2022] Open
Abstract
The expression of a gene requires not only a normal coding sequence but also intact regulatory regions, which can be located at large distances from the target genes, as demonstrated for an increasing number of developmental genes. In previous mutation studies of the role of FOXL2 in blepharophimosis syndrome (BPES), we identified intragenic mutations in 70% of our patients. Three translocation breakpoints upstream of FOXL2 in patients with BPES suggested a position effect. Here, we identified novel microdeletions outside of FOXL2 in cases of sporadic and familial BPES. Specifically, four rearrangements, with an overlap of 126 kb, are located 230 kb upstream of FOXL2, telomeric to the reported translocation breakpoints. Moreover, the shortest region of deletion overlap (SRO) contains several conserved nongenic sequences (CNGs) harboring putative transcription-factor binding sites and representing potential long-range cis-regulatory elements. Interestingly, the human region orthologous to the 12-kb sequence deleted in the polled intersex syndrome in goat, which is an animal model for BPES, is contained in this SRO, providing evidence of human-goat conservation of FOXL2 expression and of the mutational mechanism. Surprisingly, in a fifth family with BPES, one rearrangement was found downstream of FOXL2. In addition, we report nine novel rearrangements encompassing FOXL2 that range from partial gene deletions to submicroscopic deletions. Overall, genomic rearrangements encompassing or outside of FOXL2 account for 16% of all molecular defects found in our families with BPES. In summary, this is the first report of extragenic deletions in BPES, providing further evidence of potential long-range cis-regulatory elements regulating FOXL2 expression. It contributes to the enlarging group of developmental diseases caused by defective distant regulation of gene expression. Finally, we demonstrate that CNGs are candidate regions for genomic rearrangements in developmental genes.
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Affiliation(s)
- D Beysen
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
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Abstract
A 59 year old woman presented with a three year history of left sided weakness. Magnetic resonance imaging of the brain showed a large high signal lesion occupying most of the right temporal lobe with mass effect. A probable diagnosis of low grade glioma led to temporal lobectomy. Histology revealed dysplastic cortical morphology typical of tuberous sclerosis. There were no clinical signs or family history of the disease. Ultrasound showed multiple bilateral renal angiomyolipomas, confirming the diagnosis of tuberous sclerosis. Molecular genetic analysis of peripheral white blood cells identified a novel mis-sense mutation R1409W in exon 33 of the TSC2 gene.
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Affiliation(s)
- M Zarei
- Department of Clinical Neurology, Addenbrooke's Hospital, Cambridge, UK.
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