ABSTRACT
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.
Subject(s)
Adrenal Gland Neoplasms/genetics , Membrane Proteins/genetics , Paraganglioma/genetics , Pheochromocytoma/genetics , Succinate Dehydrogenase/genetics , Adrenal Gland Neoplasms/pathology , Age Factors , Aged , Aged, 80 and over , Female , Genetic Association Studies , Genotype , Germ-Line Mutation/genetics , Heterozygote , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Mutation, Missense/genetics , Paraganglioma/pathology , Pheochromocytoma/pathology , Risk Factors , Sex CharacteristicsABSTRACT
OBJECTIVES: 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 mutation-positive 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.
Subject(s)
Adrenal Gland Neoplasms/genetics , Genetic Predisposition to Disease/genetics , Head and Neck Neoplasms/genetics , Paraganglioma/genetics , Pheochromocytoma/genetics , Succinate Dehydrogenase/genetics , Von Hippel-Lindau Tumor Suppressor Protein/genetics , Adolescent , Adult , Aged , Child , Child, Preschool , Genetic Testing , Humans , Middle Aged , Prospective StudiesABSTRACT
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 45.9â¯yr) and uterine leiomyomata in 33/107 (30.8%) females (mean age 35.0â¯yr). Of 185 individuals, 23 (12.4%) had a confirmed renal tumour, and histopathology where known (nâ¯=â¯18) was variable: seven clear cell RCCs, nine papillary RCCs (six of type 2), one collecting duct tumour, and one tumour with oncocytic cystic morphology. Mean age at symptomatic RCC diagnosis was 44.0â¯yr and median survival was 21.0 mo. Eighty-one individuals underwent 187 renal imaging surveillance scans; three stage 1 RCCs were detected. Mean survival of individuals diagnosed with stage 1/2 RCC was significantly longer than those diagnosed with stage 3/4 RCC (p = 0.0004). CONCLUSIONS: Management of HLRCC is challenging as RCC occurs in a minority of cases but is highly aggressive. This large multicentre series has identified novel features and evidence that renal screening in HLRCC detects early-stage RCCs. PATIENT SUMMARY: We show that hereditary leiomyomatosis and renal cell cancer is associated with a 21% lifetime risk of renal cell carcinoma (RCC; 95% confidence interval 8.2-37.1), and renal imaging screening detects early-stage RCC.
Subject(s)
Carcinoma, Renal Cell/diagnosis , Early Detection of Cancer/methods , Fumarate Hydratase/genetics , Kidney Neoplasms/diagnosis , Leiomyomatosis/complications , Neoplastic Syndromes, Hereditary/complications , Skin Neoplasms/complications , Uterine Neoplasms/complications , Adolescent , Adult , Aged , Carcinoma, Renal Cell/genetics , Carcinoma, Renal Cell/mortality , Carcinoma, Renal Cell/therapy , DNA Mutational Analysis , Early Detection of Cancer/statistics & numerical data , Female , Follow-Up Studies , Genetic Testing/statistics & numerical data , Humans , Kidney/diagnostic imaging , Kidney Neoplasms/genetics , Kidney Neoplasms/mortality , Kidney Neoplasms/therapy , Leiomyomatosis/epidemiology , Leiomyomatosis/genetics , Leiomyomatosis/therapy , Magnetic Resonance Imaging , Male , Medical History Taking , Middle Aged , Molecular Epidemiology , Mutation , Neoplasm Staging , Neoplastic Syndromes, Hereditary/epidemiology , Neoplastic Syndromes, Hereditary/genetics , Neoplastic Syndromes, Hereditary/therapy , Prognosis , Skin Neoplasms/epidemiology , Skin Neoplasms/genetics , Skin Neoplasms/therapy , United Kingdom/epidemiology , Uterine Neoplasms/epidemiology , Uterine Neoplasms/genetics , Uterine Neoplasms/therapy , Young AdultABSTRACT
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.