The RNASEL 471delAAAG allele and prostate cancer in Ashkenazi Jewish men.

There is compelling evidence that genetic factors play an important role in prostate cancer, but no unequivocally disease causing mutations in prostate cancer susceptibility genes have been identified. In 2002, Carpten et al reported that variants in the gene RNASEL were present in some multiple case prostate cancer families. RNASEL maps to the region of chromosome 1q that has been linked to prostate cancer in multiple case prostate cancer families and this locus is often referred to as HPC1. In particular, a truncating variant, E265X, was identified in a single kindred with several cases of prostate cancer and functional analysis and the presence of loss of heterozygosity at markers close to RNASEL in one tumour supported a putative pathogenic role for this variant. However, subsequent publications have questioned the biological significance of truncating and missense variants in this gene 4 and its true importance in determining prostate cancer risk remains uncertain. Rennert et al recently identified a variant in RNASEL, known as 471delAAAG, in an Ashkenazi Jewish (AJ) man who was diagnosed with prostate cancer at the age of 65. Notably, his brother was also affected with prostate cancer at the age of 57 and was found to be homozygous for this variant. The authors then looked for this variant in 119 Israeli men with prostate cancer, among whom 87 were of AJ origin. They identified six men who carried this variant, all among the AJ males (6.9%, 95% confidence interval (CI) 2.6 to 14.4). Lower frequencies were found among elderly AJ without prostate cancer (2/83, 2.4%, 95% CI 0.29 to 8.4) and among young AJ females (6/150, 4.0%, 95% CI 1.5 to 8.5). No variants were identified in non-AJ subjects with or without prostate cancer. Limited haplotype studies indicate that the variant identified is a founder within the AJ population.