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1.
Eur Urol ; 78(4): 494-497, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32532514

RESUMO

A BRCA2 prostate cancer cluster region (PCCR) was recently proposed (c.7914 to 3') wherein pathogenic variants (PVs) are associated with higher prostate cancer (PCa) risk than PVs elsewhere in the BRCA2 gene. Using a prospective cohort study of 447 male BRCA2 PV carriers recruited in the UK and Ireland from 1998 to 2016, we estimated standardised incidence ratios (SIRs) compared with population incidences and assessed variation in risk by PV location. Carriers of PVs in the PCCR had a PCa SIR of 8.33 (95% confidence interval [CI] 4.46-15.6) and were at a higher risk of PCa than carriers of other BRCA2 PVs (SIR = 3.31, 95% CI 1.97-5.57; hazard ratio = 2.34, 95% CI 1.09-5.03). PCCR PV carriers had an estimated cumulative PCa risk of 44% (95% CI 23-72%) by the age of 75 yr and 78% (95% CI 54-94%) by the age of 85 yr. Our results corroborate the existence of a PCCR in BRCA2 in a prospective cohort. PATIENT SUMMARY: In this report, we investigated whether the risk of prostate cancer for men with a harmful mutation in the BRCA2 gene differs based on where in the gene the mutation is located. We found that men with mutations in one region of BRCA2 had a higher risk of prostate cancer than men with mutations elsewhere in the gene.

3.
Eur Urol ; 77(1): 24-35, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31495749

RESUMO

BACKGROUND: BRCA1 and BRCA2 mutations have been associated with prostate cancer (PCa) risk but a wide range of risk estimates have been reported that are based on retrospective studies. OBJECTIVE: To estimate relative and absolute PCa risks associated with BRCA1/2 mutations and to assess risk modification by age, family history, and mutation location. DESIGN, SETTING, AND PARTICIPANTS: This was a prospective cohort study of male BRCA1 (n = 376) and BRCA2 carriers (n = 447) identified in clinical genetics centres in the UK and Ireland (median follow-up 5.9 and 5.3 yr, respectively). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Standardised incidence/mortality ratios (SIRs/SMRs) relative to population incidences or mortality rates, absolute risks, and hazard ratios (HRs) were estimated using cohort and survival analysis methods. RESULTS AND LIMITATIONS: Sixteen BRCA1 and 26 BRCA2 carriers were diagnosed with PCa during follow-up. BRCA2 carriers had an SIR of 4.45 (95% confidence interval [CI] 2.99-6.61) and absolute PCa risk of 27% (95% CI 17-41%) and 60% (95% CI 43-78%) by ages 75 and 85 yr, respectively. For BRCA1 carriers, the overall SIR was 2.35 (95% CI 1.43-3.88); the corresponding SIR at age <65 yr was 3.57 (95% CI 1.68-7.58). However, the BRCA1 SIR varied between 0.74 and 2.83 in sensitivity analyses to assess potential screening effects. PCa risk for BRCA2 carriers increased with family history (HR per affected relative 1.68, 95% CI 0.99-2.85). BRCA2 mutations in the region bounded by positions c.2831 and c.6401 were associated with an SIR of 2.46 (95% CI 1.07-5.64) compared to population incidences, corresponding to lower PCa risk (HR 0.37, 95% CI 0.14-0.96) than for mutations outside the region. BRCA2 carriers had a stronger association with Gleason score ≥7 (SIR 5.07, 95% CI 3.20-8.02) than Gleason score ≤6 PCa (SIR 3.03, 95% CI 1.24-7.44), and a higher risk of death from PCa (SMR 3.85, 95% CI 1.44-10.3). Limitations include potential screening effects for these known mutation carriers; however, the BRCA2 results were robust to multiple sensitivity analyses. CONCLUSIONS: The results substantiate PCa risk patterns indicated by retrospective analyses for BRCA2 carriers, including further evidence of association with aggressive PCa, and give some support for a weaker association in BRCA1 carriers. PATIENT SUMMARY: In this study we followed unaffected men known to carry mutations in the BRCA1 and BRCA2 genes to investigate whether they are at higher risk of developing prostate cancer compared to the general population. We found that carriers of BRCA2 mutations have a high risk of developing prostate cancer, particularly more aggressive prostate cancer, and that this risk varies by family history of prostate cancer and the location of the mutation within the gene.

4.
Cancer Epidemiol Biomarkers Prev ; 29(2): 368-378, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792088

RESUMO

BACKGROUND: Tobacco smoking and alcohol consumption have been intensively studied in the general population to assess their effects on the risk of breast cancer, but very few studies have examined these effects in BRCA1 and BRCA2 mutation carriers. Given the high breast cancer risk for mutation carriers and the importance of BRCA1 and BRCA2 in DNA repair, better evidence on the associations of these lifestyle factors with breast cancer risk is essential. METHODS: Using a large international pooled cohort of BRCA1 and BRCA2 mutation carriers, we conducted retrospective (5,707 BRCA1 mutation carriers and 3,525 BRCA2 mutation carriers) and prospective (2,276 BRCA1 mutation carriers and 1,610 BRCA2 mutation carriers) analyses of alcohol and tobacco consumption using Cox proportional hazards models. RESULTS: For both BRCA1 and BRCA2 mutation carriers, none of the smoking-related variables was associated with breast cancer risk, except smoking for more than 5 years before a first full-term pregnancy (FFTP) when compared with parous women who never smoked. For BRCA1 mutation carriers, the HR from retrospective analysis (HRR) was 1.19 [95% confidence interval (CI), 1.02-1.39] and the HR from prospective analysis (HRP) was 1.36 (95% CI, 0.99-1.87). For BRCA2 mutation carriers, smoking for more than 5 years before an FFTP showed an association of a similar magnitude, but the confidence limits were wider (HRR = 1.25; 95% CI, 1.01-1.55 and HRP = 1.30; 95% CI, 0.83-2.01). For both carrier groups, alcohol consumption was not associated with breast cancer risk. CONCLUSIONS: The finding that smoking during the prereproductive years increases breast cancer risk for mutation carriers warrants further investigation. IMPACT: This is the largest prospective study of BRCA mutation carriers to assess these important risk factors.

5.
Genet Res (Camb) ; 101: e9, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31668155

RESUMO

Artificial intelligence (AI) is one of the most significant fields of development in the current digital age. Rapid advancements have raised speculation as to its potential benefits in a wide range of fields, with healthcare often at the forefront. However, amidst this optimism, apprehension and opposition continue to strongly persist. Oft-cited concerns include the threat of unemployment, harm to the doctor-patient relationship and questions of safety and accuracy. In this article, we review both the current and future medical applications of AI within the sub-speciality of cancer genomics.


Assuntos
Inteligência Artificial/tendências , Assistência à Saúde/métodos , Assistência à Saúde/tendências , Genômica , Humanos , Neoplasias , Relações Médico-Paciente
6.
Clin Med (Lond) ; 19(4): 273-277, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31308102

RESUMO

In January 2019, a new nationally commissioned Genomic Medicine Service (GMS) has now commenced in the NHS. Capitalising on the infrastructure developed through the 100,000 Genomes Project, the GMS is underpinned by seven supra-regional Genomic Laboratory Hubs (GLHs) delivering the new inherited rare disease and cancer somatic tissue genetic test directory. This replaces the UKGTN test directory, with the aim of standardising criteria for whole genome sequencing or targeted panel tests where applicable. The new test directory will define who can order specific genetic tests under prescribed eligibility criteria. In keeping with Dame Sally Davies' white paper Generation Genome, this will further democratise genetic testing and, in some situations, avoid the need to refer to clinical genetics to access testing. The aim is to simplify patient pathways and reduce regional or social inequalities. We will discuss the implications of whole genome sequencing and the potential impact of the new nationally commissioned GMS for both patients, their relatives and clinicians. We will also discuss the imminent challenges in implementing genomic medicine into the NHS, and the future impact of novel technologies on service delivery as genomic medicine becomes increasingly integrated into routine healthcare.


Assuntos
Assistência à Saúde , Testes Genéticos , Genômica , Sequenciamento Completo do Genoma , Humanos , Neoplasias/diagnóstico , Neoplasias/genética , Doenças Raras/diagnóstico , Doenças Raras/genética
7.
Am J Hum Genet ; 103(1): 3-18, 2018 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-29909963

RESUMO

Multiple primary tumors (MPTs) affect a substantial proportion of cancer survivors and can result from various causes, including inherited predisposition. Currently, germline genetic testing of MPT-affected individuals for variants in cancer-predisposition genes (CPGs) is mostly targeted by tumor type. We ascertained pre-assessed MPT individuals (with at least two primary tumors by age 60 years or at least three by 70 years) from genetics centers and performed whole-genome sequencing (WGS) on 460 individuals from 440 families. Despite previous negative genetic assessment and molecular investigations, pathogenic variants in moderate- and high-risk CPGs were detected in 67/440 (15.2%) probands. WGS detected variants that would not be (or were not) detected by targeted resequencing strategies, including low-frequency structural variants (6/440 [1.4%] probands). In most individuals with a germline variant assessed as pathogenic or likely pathogenic (P/LP), at least one of their tumor types was characteristic of variants in the relevant CPG. However, in 29 probands (42.2% of those with a P/LP variant), the tumor phenotype appeared discordant. The frequency of individuals with truncating or splice-site CPG variants and at least one discordant tumor type was significantly higher than in a control population (χ2 = 43.642; p ≤ 0.0001). 2/67 (3%) probands with P/LP variants had evidence of multiple inherited neoplasia allele syndrome (MINAS) with deleterious variants in two CPGs. Together with variant detection rates from a previous series of similarly ascertained MPT-affected individuals, the present results suggest that first-line comprehensive CPG analysis in an MPT cohort referred to clinical genetics services would detect a deleterious variant in about a third of individuals.


Assuntos
Predisposição Genética para Doença/genética , Variação Genética/genética , Neoplasias Primárias Múltiplas/genética , Adulto , Idoso , Biomarcadores Tumorais/genética , Feminino , Testes Genéticos/métodos , Mutação em Linhagem Germinativa/genética , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo
8.
Genet Med ; 20(12): 1575-1582, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29565421

RESUMO

PURPOSE: BRCA1/BRCA2 predictive test negatives are proven noncarriers of a BRCA1/BRCA2 mutation that is carried by their relatives. The risk of developing breast cancer (BC) or epithelial ovarian cancer (EOC) in these women is uncertain. The study aimed to estimate risks of invasive BC and EOC in a large cohort of BRCA1/BRCA2 predictive test negatives. METHODS: We used cohort analysis to estimate incidences, cumulative risks, and standardized incidence ratios (SIRs). RESULTS: A total of 1,895 unaffected women were eligible for inclusion in the BC risk analysis and 1,736 in the EOC risk analysis. There were 23 incident invasive BCs and 2 EOCs. The cumulative risk of invasive BC was 9.4% (95% confidence interval (CI) 5.9-15%) by age 85 years and the corresponding risk of EOC was 0.6% (95% CI 0.2-2.6%). The SIR for invasive BC was 0.93 (95% CI 0.62-1.40) in the overall cohort, 0.85 (95% CI 0.48-1.50) in noncarriers from BRCA1 families, and 1.03 (95% CI 0.57-1.87) in noncarriers from BRCA2 families. The SIR for EOC was 0.79 (95% CI 0.20-3.17) in the overall cohort. CONCLUSION: Our results did not provide evidence for elevated risks of invasive BC or EOC in BRCA1/BRCA2 predictive test negatives.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/genética , Neoplasias Ovarianas/genética , Adulto , Idoso , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/epidemiologia , Medição de Risco , Fatores de Risco
9.
J Med Genet ; 55(6): 384-394, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29386252

RESUMO

BACKGROUND: Germline pathogenic variants in SDHB/SDHC/SDHD are the most frequent causes of inherited phaeochromocytomas/paragangliomas. Insufficient information regarding penetrance and phenotypic variability hinders optimum management of mutation carriers. We estimate penetrance for symptomatic tumours and elucidate genotype-phenotype correlations in a large cohort of SDHB/SDHC/SDHD mutation carriers. METHODS: A retrospective survey of 1832 individuals referred for genetic testing due to a personal or family history of phaeochromocytoma/paraganglioma. 876 patients (401 previously reported) had a germline mutation in SDHB/SDHC/SDHD (n=673/43/160). Tumour risks were correlated with in silico structural prediction analyses. RESULTS: Tumour risks analysis provided novel penetrance estimates and genotype-phenotype correlations. In addition to tumour type susceptibility differences for individual genes, we confirmed that the SDHD:p.Pro81Leu mutation has a distinct phenotype and identified increased age-related tumour risks with highly destabilising SDHB missense mutations. By Kaplan-Meier analysis, the penetrance (cumulative risk of clinically apparent tumours) in SDHB and (paternally inherited) SDHD mutation-positive non-probands (n=371/67 with detailed clinical information) by age 60 years was 21.8% (95% CI 15.2% to 27.9%) and 43.2% (95% CI 25.4% to 56.7%), respectively. Risk of malignant disease at age 60 years in non-proband SDHB mutation carriers was 4.2%(95% CI 1.1% to 7.2%). With retrospective cohort analysis to adjust for ascertainment, cumulative tumour risks for SDHB mutation carriers at ages 60 years and 80 years were 23.9% (95% CI 20.9% to 27.4%) and 30.6% (95% CI 26.8% to 34.7%). CONCLUSIONS: Overall risks of clinically apparent tumours for SDHB mutation carriers are substantially lower than initially estimated and will improve counselling of affected families. Specific genotype-tumour risk associations provides a basis for novel investigative strategies into succinate dehydrogenase-related mechanisms of tumourigenesis and the development of personalised management for SDHB/SDHC/SDHD mutation carriers.


Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Proteínas de Membrana/genética , Paraganglioma/genética , Feocromocitoma/genética , Succinato Desidrogenase/genética , Neoplasias das Glândulas Suprarrenais/patologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Estudos de Associação Genética , Genótipo , Mutação em Linhagem Germinativa/genética , Heterozigoto , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto/genética , Paraganglioma/patologia , Feocromocitoma/patologia , Fatores de Risco , Caracteres Sexuais
11.
Histopathology ; 71(1): 42-52, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28165631

RESUMO

AIMS: Fumarate hydratase (FH)-deficient renal cell carcinoma (RCC) is a high-grade, aggressive tubulopapillary carcinoma, arising predominantly in the setting of the hereditary leiomyomatosis-RCC syndrome of familial uterocutaneous leiomyomatosis and deficiency of FH. In contrast, succinate dehydrogenase (SDH)-deficient RCC is a lower-grade oncocytic carcinoma with cytoplasmic flocculence/vacuolation and inclusions, arising mostly in individuals harbouring germline mutations of subunit B of the SDH complex (SDHB). Herein we aim to report the clinicopathologic features of a novel form of FH-deficient RCC showing a low grade oncocytic morphology, reminiscent of SDH-deficient RCC. METHODS AND RESULTS: These distinctive, low-grade oncocytic neoplasms, with solid, nested and focally tubular architecture (2-90 mm), arose in four males (aged 11-41 years). Uniform cytology of polygonal cells, with flocculent, vacuolated eosinophilic cytoplasm with scattered inclusions, fine chromatin, and inconspicuous nucleoli, was apparent. Despite these features suggestive of SDH-deficient RCC, each tumour was confirmed as an FH-deficient carcinoma with retained SDHB expression. One case showed a synchronous, anatomically separate, typical high-grade FH-deficient RCC; one other showed such a tumour at nephrectomy 4 years later. No progression has been noted at 3 and 7 years in the cases with only the SDH-like lesions; the two cases with separate, typical FH-deficient RCCs progressed. CONCLUSIONS: In summary, we characterize a novel oncocytic type of FH-deficient RCC with a striking resemblance to SDH-deficient RCC, posing a diagnostic challenge and raising concerns about sampling and multifocality for syndrome-associated cases under surveillance protocols.


Assuntos
Carcinoma de Células Renais/patologia , Fumarato Hidratase/deficiência , Neoplasias Renais/patologia , Adulto , Carcinoma de Células Renais/enzimologia , Criança , Humanos , Neoplasias Renais/enzimologia , Masculino , Succinato Desidrogenase
12.
F1000Res ; 5: 386, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27158454

RESUMO

To provide a useful community resource for orthogonal assessment of NGS analysis software, we present the ICR142 NGS validation series. The dataset includes high-quality exome sequence data from 142 samples together with Sanger sequence data at 704 sites; 416 sites with variants and 288 sites at which variants were called by an NGS analysis tool, but no variant is present in the corresponding Sanger sequence. The dataset includes 293 indel variants and 247 negative indel sites, and thus the ICR142 validation dataset is of particular utility in evaluating indel calling performance. The FASTQ files and Sanger sequence results can be accessed in the European Genome-phenome Archive under the accession number EGAS00001001332.

13.
Springerplus ; 4: 632, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26543766

RESUMO

BACKGROUND: Head and neck paragangliomas are rare tumours and can arise as a part of inherited syndromes. Their association with thymic tumour is not well known. CASE DESCRIPTION: This report describes a female patient who presented with right sided neck paragangliomas. The histology of the tumour was consistent with paraganlioma. Few years later her MRI scan of the chest revealed presence of an anterior mediastinal mass that corresponded to the location of the thymus. Review of her previous scans showed that the mass was present all along and had gradually increased in size. Patient developed symptoms including fatigue, dyspnoea, migratory polyarthritis, Raynaud's phenomenon and erythema nodosum. She had sternotomy and excision of mediastinal mass. The histology was consistent with cortical thymoma (WHO type B2) and she had radiotherapy. After treatment her constitutional symptoms improved. Her paraganglioma susceptibility genes are negative. DISCUSSION AND EVALUATION: To our knowledge this is only the second case report in the literature of coexistence of carotid body tumour and thymoma. The first case reported was bilateral carotid body tumour, thyroid gland adenoma and thymoma. This case also highlights the importance of long term surveillance, multidisciplinary management and being aware of associated pathologies in patients with isolated paraganglioma.

14.
Hum Mutat ; 36(11): 1112, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26457590

RESUMO

The original article to which this Erratum refers was published in Human Mutation 36(6):593­598(DOI:10.1002/humu22795).The authors realized that a co-author, Nuria C. Bramswig, was left off of the title page of this article at the time of submission. This erratum serves to correct this error by including Dr. Bramswig and Dr. Bramswig's institution in the title page information.The authors regret the error.

15.
Circ Cardiovasc Genet ; 8(4): 572-581, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25963545

RESUMO

BACKGROUND: Adams-Oliver syndrome (AOS) is a rare disorder characterized by congenital limb defects and scalp cutis aplasia. In a proportion of cases, notable cardiac involvement is also apparent. Despite recent advances in the understanding of the genetic basis of AOS, for the majority of affected subjects, the underlying molecular defect remains unresolved. This study aimed to identify novel genetic determinants of AOS. METHODS AND RESULTS: Whole-exome sequencing was performed for 12 probands, each with a clinical diagnosis of AOS. Analyses led to the identification of novel heterozygous truncating NOTCH1 mutations (c.1649dupA and c.6049_6050delTC) in 2 kindreds in which AOS was segregating as an autosomal dominant trait. Screening a cohort of 52 unrelated AOS subjects, we detected 8 additional unique NOTCH1 mutations, including 3 de novo amino acid substitutions, all within the ligand-binding domain. Congenital heart anomalies were noted in 47% (8/17) of NOTCH1-positive probands and affected family members. In leukocyte-derived RNA from subjects harboring NOTCH1 extracellular domain mutations, we observed significant reduction of NOTCH1 expression, suggesting instability and degradation of mutant mRNA transcripts by the cellular machinery. Transient transfection of mutagenized NOTCH1 missense constructs also revealed significant reduction in gene expression. Mutant NOTCH1 expression was associated with downregulation of the Notch target genes HEY1 and HES1, indicating that NOTCH1-related AOS arises through dysregulation of the Notch signaling pathway. CONCLUSIONS: These findings highlight a key role for NOTCH1 across a range of developmental anomalies that include cardiac defects and implicate NOTCH1 haploinsufficiency as a likely molecular mechanism for this group of disorders.


Assuntos
Displasia Ectodérmica/genética , Predisposição Genética para Doença/genética , Haploinsuficiência , Cardiopatias Congênitas/genética , Deformidades Congênitas dos Membros/genética , Receptor Notch1/genética , Dermatoses do Couro Cabeludo/congênito , Adolescente , Adulto , Sequência de Bases , Criança , Exoma/genética , Saúde da Família , Feminino , Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Linhagem , Estrutura Terciária de Proteína , Receptor Notch1/química , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Dermatoses do Couro Cabeludo/genética , Análise de Sequência de DNA/métodos , Transdução de Sinais/genética , Adulto Jovem
16.
Hum Mutat ; 36(6): 593-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25824905

RESUMO

Adams-Oliver syndrome (AOS) is characterized by the association of aplasia cutis congenita with terminal transverse limb defects, often accompanied by additional cardiovascular or neurological features. Both autosomal-dominant and autosomal-recessive disease transmission have been observed, with recent gene discoveries indicating extensive genetic heterogeneity. Mutations of the DOCK6 gene were first described in autosomal-recessive cases of AOS and only five DOCK6-related families have been reported to date. Recently, a second type of autosomal-recessive AOS has been attributed to EOGT mutations in three consanguineous families. Here, we describe the identification of 13 DOCK6 mutations, the majority of which are novel, across 10 unrelated individuals from a large cohort comprising 47 sporadic cases and 31 AOS pedigrees suggestive of autosomal-recessive inheritance. DOCK6 mutations were strongly associated with structural brain abnormalities, ocular anomalies, and intellectual disability, thus suggesting that DOCK6-linked disease represents a variant of AOS with a particularly poor prognosis.


Assuntos
Encéfalo/anormalidades , Displasia Ectodérmica/diagnóstico , Displasia Ectodérmica/genética , Anormalidades do Olho/genética , Genes Recessivos , Estudos de Associação Genética , Fatores de Troca do Nucleotídeo Guanina/genética , Deformidades Congênitas dos Membros/diagnóstico , Deformidades Congênitas dos Membros/genética , Mutação , Dermatoses do Couro Cabeludo/congênito , Adolescente , Encéfalo/patologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Imagem por Ressonância Magnética , Masculino , Dermatoses do Couro Cabeludo/diagnóstico , Dermatoses do Couro Cabeludo/genética , Tomografia Computadorizada por Raios X , Adulto Jovem
18.
J Clin Endocrinol Metab ; 99(7): E1300-5, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24708097

RESUMO

CONTEXT: Autosomal dominant hypocalcemia (ADH) types 1 and 2 are due to calcium-sensing receptor (CASR) and G-protein subunit-α11 (GNA11) gain-of-function mutations, respectively, whereas CASR and GNA11 loss-of-function mutations result in familial hypocalciuric hypercalcemia (FHH) types 1 and 2, respectively. Loss-of-function mutations of adaptor protein-2 sigma subunit (AP2σ 2), encoded by AP2S1, cause FHH3, and we therefore sought for gain-of-function AP2S1 mutations that may cause an additional form of ADH, which we designated ADH3. OBJECTIVE: The objective of the study was to investigate the hypothesis that gain-of-function AP2S1 mutations may cause ADH3. DESIGN: The sample size required for the detection of at least one mutation with a greater than 95% likelihood was determined by binomial probability analysis. Nineteen patients (including six familial cases) with hypocalcemia in association with low or normal serum PTH concentrations, consistent with ADH, but who did not have CASR or GNA11 mutations, were ascertained. Leukocyte DNA was used for sequence and copy number variation analysis of AP2S1. RESULTS: Binomial probability analysis, using the assumption that AP2S1 mutations would occur in hypocalcemic patients at a prevalence of 20%, which is observed in FHH patients without CASR or GNA11 mutations, indicated that the likelihood of detecting at least one AP2S1 mutation was greater than 95% and greater than 98% in sample sizes of 14 and 19 hypocalcemic patients, respectively. AP2S1 mutations and copy number variations were not detected in the 19 hypocalcemic patients. CONCLUSION: The absence of AP2S1 abnormalities in hypocalcemic patients, suggests that ADH3 may not occur or otherwise represents a rare hypocalcemic disorder.


Assuntos
Complexo 2 de Proteínas Adaptadoras/genética , Subunidades sigma do Complexo de Proteínas Adaptadoras/genética , Hipercalciúria/genética , Hipocalcemia/genética , Hipoparatireoidismo/congênito , Adulto , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Frequência do Gene , Humanos , Hipoparatireoidismo/genética , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
19.
Nature ; 493(7432): 406-10, 2013 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-23242139

RESUMO

Improved sequencing technologies offer unprecedented opportunities for investigating the role of rare genetic variation in common disease. However, there are considerable challenges with respect to study design, data analysis and replication. Using pooled next-generation sequencing of 507 genes implicated in the repair of DNA in 1,150 samples, an analytical strategy focused on protein-truncating variants (PTVs) and a large-scale sequencing case-control replication experiment in 13,642 individuals, here we show that rare PTVs in the p53-inducible protein phosphatase PPM1D are associated with predisposition to breast cancer and ovarian cancer. PPM1D PTV mutations were present in 25 out of 7,781 cases versus 1 out of 5,861 controls (P = 1.12 × 10(-5)), including 18 mutations in 6,912 individuals with breast cancer (P = 2.42 × 10(-4)) and 12 mutations in 1,121 individuals with ovarian cancer (P = 3.10 × 10(-9)). Notably, all of the identified PPM1D PTVs were mosaic in lymphocyte DNA and clustered within a 370-base-pair region in the final exon of the gene, carboxy-terminal to the phosphatase catalytic domain. Functional studies demonstrate that the mutations result in enhanced suppression of p53 in response to ionizing radiation exposure, suggesting that the mutant alleles encode hyperactive PPM1D isoforms. Thus, although the mutations cause premature protein truncation, they do not result in the simple loss-of-function effect typically associated with this class of variant, but instead probably have a gain-of-function effect. Our results have implications for the detection and management of breast and ovarian cancer risk. More generally, these data provide new insights into the role of rare and of mosaic genetic variants in common conditions, and the use of sequencing in their identification.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença/genética , Mosaicismo , Mutação , Neoplasias Ovarianas/genética , Fosfoproteínas Fosfatases/genética , Alelos , Análise por Conglomerados , Éxons , Feminino , Humanos , Isoenzimas/genética , Linfócitos/metabolismo , Proteína Fosfatase 2C , Análise de Sequência de DNA , Proteína Supressora de Tumor p53/metabolismo
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