BackgroundGermline 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.MethodsA 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.ResultsTumour 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%).ConclusionsOverall 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.

Context: Pheochromocytomas and paragangliomas are notable for a high frequency of inherited cases, many of which present as apparently sporadic tumors.Objective: The objective of this study was to establish a comprehensive next generation sequencing (NGS)-based strategy for the diagnosis of patients with pheochromocytoma and paraganglioma by testing simultaneously for mutations in MAX, RET, SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, and VHL. Design: After the methodology for the assay was designed and established, it was validated on DNA samples with known genotype and then patients were studied prospectively. Setting:The study was performed in a diagnostic genetics laboratory.Patients: DNA samples from 205 individuals affected with adrenal or extraadrenal pheochromocytoma/head and neck paraganglioma (PPGL/HNPGL) were analyzed. A proof-of-principle study was performed using 85 samples known to contain a variant in 1 or more of the genes to be tested, followed by prospective analysis of an additional 120 samples. Main Outcome Measures:We assessed the ability to use an NGS-based method to perform comprehensive analysis of genes implicated in inherited PPGL/HNPGL. Results:The proof-of-principle study showed that the NGS assay and analysis gave a sensitivity of 98.7%. A pathogenic mutation was identified in 16.6% of the prospective analysis cohort of 120 patients. Conclusions:A comprehensive NGS-based strategy for the analysis of genes associated with predisposition to PPGL and HNPGL was established, validated, and introduced into diagnostic service. The new assay provides simultaneous analysis of 9 genes and allows more rapid and cost-effective mutation detection than the previously used conventional Sanger sequencing-based methodology. (J Clin Endocrinol Metab 98: E1248 -E1256, 2013) P heochromocytomas and paragangliomas are rare, mostly benign, tumors that are notable for a high frequency of inherited cases (1-5). Both pheochromocytomas (which arise from the adrenal medulla) and paragangliomas (also known as extraadrenal pheochromocytomas) (together referred to as PPGLs) usually present with symptoms caused by the cardiovascular effects of excess catecholamine secretion. Head and neck paragangliomas (HNPGLs) are generally nonfunctional and are derived from parasympathetic ganglia. Before 2000, about 10% of PPGLs were thought to be inherited (6) and mostly associated with defined clinical syndromes: von

Background: Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a tumour predisposition syndrome characterised by predisposition to cutaneous and uterine leiomyomata and renal cell carcinoma (RCC). Objective: To define the clinical findings, molecular genetics, and prognosis in a cohort of 69 families with a fumarate hydratase (FH) pathogenic variant and/or clinical features of HLRCC. Design, setting, and participants: Clinical and molecular findings were obtained for 185 individuals from 69 families from four UK regional genetics clinics. Outcome measurements and statistical analysis: Ages at confirmed diagnoses, last dates of follow-up, and molecular results were attained for probands and relatives. To study the effect of potential ascertainment bias, phenotypes of probands and their affected relatives were compared. Results and limitations: A germline FH variant (19 novel and 21 known, >50% missense variants) was identified in 68/69 probands and 90 relatives. Cutaneous leiomyomata occurred in 90/185 (48.6%) individuals (mean age 45.9 yr) and uterine leiomyomata in 33/107 (30.8%) females (mean age 35.0 yr). Of 185 individuals, 23 (12.4%) had a confirmed renal tumour, and histopathology where known (n = 18)

SummaryObjectives Research studies have reported that about a third of individuals with phaeochromocytoma/paraganglioma (PPGL) have an inherited predisposition, although the frequency of specific mutations can vary between populations. We evaluated VHL, SDHB and SDHD mutation testing in cohorts of patients with non-syndromic PPGL and head and neck paraganglioma (HNPGL). Design Prospective, observational evaluation of NHS practice. Patients Individuals with PPGL/HNPGL referred to a supraregional genetics testing service over a 10-year period. Measurements Clinical (age, tumour site, malignancy, etc.), mutation frequencies and characteristics.Results A total of 501 probands with PPGL (n = 413) or HNPGL (n = 88) were studied. Thirty-one percent of patients with PPGL presented had a pathogenic mutation in SDHB, SDHD or VHL. Mutation detection rates were highest in those with a positive family history (62%), malignancy (53%), multiple tumours (33%) or PGL (44%). Twenty-eight percent of individuals with a single sporadic phaeochromocytoma had a mutation. Overall, 63% of patients with HNPGL had a mutation (92% of those with a family history, 89% of those with multicentric tumours and 34% of those with a single sporadic HNPGL). Penetrance was calculated in 121 SDHB mutation-positive probands and 187 of their mutationpositive relatives. Most relatives were asymptomatic and lifetime penetrance in non-proband SDHB mutation carriers was <50%. Conclusions Practice-based evaluations of genetic testing in PPGL reveal high mutation detection rates. Although clinical criteria can be used to prioritize mutation testing, mutations were detected in 'low risk groups' indicating a need for comprehensive and inexpensive genetic testing strategies for PPGL and HNPGL.

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