RESUMO
Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant cancer predisposition syndrome characterized by cutaneous leiomyomas, uterine leiomyomas, and aggressive renal cancer. Germline variants in the fumarate hydratase (FH) gene predispose to HLRCC. Identifying germline pathogenic FH variants enables lifetime renal cancer screening and genetic testing for family members. In this report, we present a FH missense variant (c.1039T>C (p.S347P)), initially classified as a variant of uncertain significance. Clinical assessment, histopathological findings, molecular genetic studies, and enzymatic activity studies support the re-classification of the FH c.1039T>C variant to "pathogenic" based on ACMG/AMP criteria. Further insights into pathological recognition of FH-deficient renal cancer are discussed and should be recognized. This study has shown how (a) detailed multi-disciplinary analyses of a single variant can reclassify rare missense variants in FH and (b) careful pathological review of renal cancers is obligatory when HLRCC is suspected.
Assuntos
Fumarato Hidratase , Leiomiomatose , Mutação de Sentido Incorreto , Síndromes Neoplásicas Hereditárias , Neoplasias Cutâneas , Neoplasias Uterinas , Humanos , Fumarato Hidratase/genética , Leiomiomatose/genética , Leiomiomatose/patologia , Feminino , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Neoplasias Uterinas/genética , Neoplasias Uterinas/patologia , Síndromes Neoplásicas Hereditárias/genética , Síndromes Neoplásicas Hereditárias/patologia , Neoplasias Renais/genética , Neoplasias Renais/patologia , Linhagem , Mutação em Linhagem Germinativa , Masculino , Adulto , Predisposição Genética para Doença , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: Pulmonary blastoma is a rare, biphasic, adult-onset lung tumor. In this study, we investigate whether DICER1 pathogenic variants are a feature of pulmonary blastomas through in-depth analysis of the molecular events defining them. METHODS: We performed exome-wide sequencing and DNA methylation profiling of 8 pulmonary blastomas from 6 affected persons. RESULTS: We identified biallelic somatic DICER1 pathogenic variants in 7 of 8 cases. The remaining case had a solitary missense pathogenic variant in the RNase IIIb domain of DICER1. Six of 8 cases carried a CTNNB1 hotspot variant and 4 of 8 had a somatic pathogenic variant in TP53. Methylation analysis showed that the pulmonary blastomas clustered with other DICER1-mutated tumors and not with other more common types of lung cancer. CONCLUSION: We conclude somatic DICER1 pathogenic variants are the major driver of pulmonary blastoma and are likely to act in conjunction with CTNNB1 hotspot variants that are often present.
RESUMO
It was hypothesized that variants in underexplored homologous recombination repair (HR) genes could explain unsolved multiple-case breast cancer (BC) families. We investigated HR deficiency (HRD)-associated mutational signatures and second hits in tumor DNA from familial BC cases. No candidates genes were associated with HRD in 38 probands previously tested negative with gene panels. We conclude it is unlikely that unknown HRD-associated genes explain a large fraction of unsolved familial BC.