Multifocal renal cell carcinoma in sibs from a chromosome 9 linked (TSC1) tuberous sclerosis family.

Multifocal renal cell carcinomas (RCCs), together with angiomyolipomas (AMLs) and renal cysts, were identified in early adult life in two sisters with tuberous sclerosis (TSC). They were members of a multigenerational tuberous sclerosis family showing strong evidence for a mutant TSC causing gene on chromosome 9 (TSC1). Previous reports of multifocal RCC in young patients with TSC suggest that constitutional mutations at the TSC loci may predispose to RCC. In the rat a germline mutation affecting the TSC2 gene is associated with transmission of multifocal RCC as an autosomal dominant trait. However, the cases reported here are the first to suggest a similar role for the TSC1 gene in renal cell carcinogenesis.