Frequent hSNF5/INI1 Germline Mutations in Patients with Rhabdoid Tumor

Purpose: Germline hSNF5/INI1 mutations are responsible for hereditary cases of rhabdoid tumors (RT) that constitute the rhabdoid predisposition syndrome (RPS). Our study provides the first precise overview of the prevalence of RPS within a large cohort of RT. Experimental Design: hSNF5/INI1 coding exons were investigated by sequencing and by multiplex ligation-dependent probe amplification. Results: Seventy-four constitutional DNAs from 115 apparently sporadic RT were analyzed from 1999 to 2009. Germline mutations were found in 26 patients (35%). Data from 9 individuals from 5 RPS families (siblings) were also studied. The median age at diagnosis was much lower (6 months) in patients with germline mutation ( P de novo mutations in RPS. The former hypothesis could be clearly documented in 1 case in which prenatal diagnosis was positive in a new pregnancy. Finally, the 2 years9 overall survival was 7% in mutated and 29% in wild-type patients, mainly due to the worse outcome of RT in younger patients. Conclusions: Our results show a high proportion of germline mutations in patients with RT that can be found at any age and up to 60% in the youngest patients. Genetic counseling is recommended given the low but actual risk of familial recurrence. Clin Cancer Res; 17(1); 31–8. ©2011 AACR .