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Lettice L.A.,Institute of Genetics and Molecular Medicine | Daniels S.,Institute of Genetics and Molecular Medicine | Daniels S.,University of Edinburgh | Sweeney E.,Cheshire and Merseyside Clinical Genetics Service | And 7 more authors.
Human Mutation | Year: 2011

Disruption of the long-range cis-regulation of developmental gene expression is increasingly recognized as a cause of human disease. Here, we report a novel type of long-range cis-regulatory mutation, in which ectopic expression of a gene is driven by an enhancer that is not its own. We have termed this gain of regulatory information as "enhancer adoption." We mapped the breakpoints of a de novo 7q inversion in a child with features of a holoprosencephaly spectrum (HPES) disorder and severe upper limb syndactyly with lower limb synpolydactyly. The HPES plausibly results from the 7q36.3 breakpoint dislocating the sonic hedgehog (SHH) gene from enhancers that are known to drive expression in the early forebrain. However, the limb phenotype cannot be explained by loss of known SHH enhancers. The SHH transcription unit is relocated to 7q22.1, ~190 kb 3′ of a highly conserved noncoding element (HCNE2) within an intron of EMID2. We show that HCNE2 functions as a limb bud enhancer in mouse embryos and drives ectopic expression of Shh in vivo recapitulating the limb phenotype in the child. This developmental genetic mechanism may explain a proportion of the novel or unexplained phenotypes associated with balanced chromosome rearrangements. © 2011 Wiley Periodicals, Inc. Source


Johnston J.J.,Human Genome Research Institutes | Sapp J.C.,Human Genome Research Institutes | Turner J.T.,Human Genome Research Institutes | Amor D.,Murdoch Childrens Research Institute | And 50 more authors.
Human Mutation | Year: 2010

A range of phenotypes including Greig cephalopolysyndactyly and Pallister-Hall syndromes (GCPS, PHS) are caused by pathogenic mutation of the GLI3 gene. To characterize the clinical variability of GLI3 mutations, we present a subset of a cohort of 174 probands referred for GLI3 analysis. Eighty-one probands with typical GCPS or PHS were previously reported, and we report the remaining 93 probands here. This includes 19 probands (12 mutations) who fulfilled clinical criteria for GCPS or PHS, 48 probands (16 mutations) with features of GCPS or PHS but who did not meet the clinical criteria (sub-GCPS and sub-PHS), 21 probands (6 mutations) with features of PHS or GCPS and oral-facial-digital syndrome, and 5 probands (1 mutation) with nonsyndromic polydactyly. These data support previously identified genotype-phenotype correlations and demonstrate a more variable degree of severity than previously recognized. The finding of GLI3 mutations in patients with features of oral-facial-digital syndrome supports the observation that GLI3 interacts with cilia. We conclude that the phenotypic spectrum of GLI3 mutations is broader than that encompassed by the clinical diagnostic criteria, but the genotype-phenotype correlation persists. Individuals with features of either GCPS or PHS should be screened for mutations in GLI3 even if they do not fulfill clinical criteria. © 2010 Wiley-Liss, Inc. Source


Pooley K.A.,University of Cambridge | McGuffog L.,University of Cambridge | Barrowdale D.,University of Cambridge | Frost D.,University of Cambridge | And 32 more authors.
Cancer Epidemiology Biomarkers and Prevention | Year: 2014

Background: Telomere length has been linked to risk of common diseases, including cancer, and has previously been proposed as a biomarker for cancer risk. Germline BRCA1 and BRCA2 mutations predispose to breast, ovarian, and other cancer types. Methods: We investigated telomere length in BRCA mutation carriers and their non-carrier relatives and further examined whether telomere length is a modifier of cancer risk in mutation carriers. We measured mean telomere length in DNA extracted from whole blood using high-throughput quantitative PCR. Participants were from the EMBRACE study in United Kingdom and Eire ( n = 4,822) and comprised BRCA1 (n = 1,628) and BRCA2 (n = 1,506) mutation carriers and their non-carrier relatives (n = 1,688). Results: We find no significant evidence that mean telomere length is associated with breast or ovarian cancer risk in BRCA mutation carriers. However, we find mutation carriers to have longer mean telomere length than their non-carrier relatives (all carriers vs. non-carriers, Ptrend = 0.0018), particularly in families with BRCA2 mutations (BRCA2 mutation carriers vs. all non-carriers, Ptrend = 0.0016). Conclusions: Our findings lend little support to the hypothesis that short mean telomere length predisposes to cancer. Conversely, our main and unexpected finding is that BRCA mutation carriers (regardless of cancer status) have longer telomeres than their non-mutation carrier, non-cancer-affected relatives. The longer telomere length in BRCA2 mutation carriers is consistent with its role in DNA damage response. Overall, it seems that increased telomere length may be a consequence of these mutations, but is not itself directly related to the increased cancer risk in carriers. Impact: The finding that mutation carriers have longer mean telomere lengths than their non-carrier relatives is unexpected but biologically plausible and could open up new lines of research into the functions of the BRCA proteins. To our knowledge, this is the largest study of telomere length in BRCA mutation carriers and their relatives. The null cancer-risk association supports recent large prospective studies of breast and ovarian cancer and indicates that mean telomere length would not be a useful biomarker in these cancers. ©2014 AACR. Source


Mavaddat N.,Center for Cancer Genetic Epidemiology | Peock S.,Center for Cancer Genetic Epidemiology | Frost D.,Center for Cancer Genetic Epidemiology | Ellis S.,Center for Cancer Genetic Epidemiology | And 31 more authors.
Journal of the National Cancer Institute | Year: 2013

Background Reliable estimates of cancer risk are critical for guiding management of BRCA1 and BRCA2 mutation carriers. The aims of this study were to derive penetrance estimates for breast cancer, ovarian cancer, and contralateral breast cancer in a prospective series of mutation carriers and to assess how these risks are modified by common breast cancer susceptibility alleles. Methods Prospective cancer risks were estimated using a cohort of 978 BRCA1 and 909 BRCA2 carriers from the United Kingdom. Nine hundred eighty-eight women had no breast or ovarian cancer diagnosis at baseline, 1509 women were unaffected by ovarian cancer, and 651 had been diagnosed with unilateral breast cancer. Cumulative risks were obtained using Kaplan-Meier estimates. Associations between cancer risk and covariables of interest were evaluated using Cox regression. All statistical tests were two-sided. Results The average cumulative risks by age 70 years for BRCA1 carriers were estimated to be 60% (95% confidence interval [CI] = 44% to 75%) for breast cancer, 59% (95% CI = 43% to 76%) for ovarian cancer, and 83% (95% CI = 69% to 94%) for contralateral breast cancer. For BRCA2 carriers, the corresponding risks were 55% (95% CI = 41% to 70%) for breast cancer, 16.5% (95% CI = 7.5% to 34%) for ovarian cancer, and 62% (95% CI = 44% to 79.5%) for contralateral breast cancer. BRCA2 carriers in the highest tertile of risk, defined by the joint genotype distribution of seven single nucleotide polymorphisms associated with breast cancer risk, were at statistically significantly higher risk of developing breast cancer than those in the lowest tertile (hazard ratio = 4.1, 95% CI = 1.2 to 14.5; P =. 02). Conclusions Prospective risk estimates confirm that BRCA1 and BRCA2 carriers are at high risk of developing breast, ovarian, and contralateral breast cancer. Our results confirm findings from retrospective studies that common breast cancer susceptibility alleles in combination are predictive of breast cancer risk for BRCA2 carriers. © 2013 The Author. Source


White H.D.,North Wales NHS Trust | Blair J.,Royal Liverpool Childrens NHS Trust | Pinkney J.,Foundation University | Cuthbertson D.J.,Foundation University | And 3 more authors.
QJM | Year: 2010

Background: Multiple endocrine neoplasia type 1 (MEN1) is associated with significant morbidity and mortality. Timely detection of MEN1 kindred, together with treatment of associated tumours, results in an improved outcome. We describe how the development of a dedicated multidisciplinary MEN clinic has improved the diagnosis and treatment of MEN1-associated endocrinopathies. Design and patients: A dedicated MEN clinic was developed at Aintree University Hospital, Liverpool in 2002 for patients living in Merseyside, Cheshire and North Wales. The multidisciplinary approach adopted, aimed to improve communication and continuity of care. Patients see all clinicians involved in their care (Consultant Endocrinologist, Paediatrician, Clinical Geneticist and Endocrine Surgeon) simultaneously, allowing for a unified, clear approach and a reduction in unnecessary attendances. The clinicians adopt a proactive approach to tracing the relatives of patients, with the aim of identifying kindred with previously asymptomatic disease. Results: In 2002, 16 patients from 5 families were diagnosed clinically with MEN1. Twenty MEN1-associated endocrinopathies had been diagnosed and 21 surgical procedures had been performed. By the end of 2008, 45 patients from 15 families had been identified, with 83 endocrinopathies diagnosed and 50 surgical procedures performed. Ninety-four known relatives are awaiting screening for MEN1. Conclusion: The successful identification of patients with MEN1 has resulted in an exponential increase in the number of patients attending the clinic. As relatives undergo screening, the diagnosis of MEN is likely to increase. The ever increasing numbers of patients requiring screening, surveillance and treatment has implications in the planning of future service provision. © The Author 2010. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org. Source

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