BACKGROUND: We previously identified a novel exogenous gammaretrovirus (xenotropic murine leukemia virus-related gammaretrovirus (XMRV)) using a pan-viral microarray. XMRV is the first MLV-related virus found in human infection. Forty percent (8/20) of familial prostate cancer patients homozygous for a mutation in RNase L (R462Q) were positive for XMRV, while the virus was rarely (1/66) detected in familial prostate cancer patients heterozygous for R462Q or carrying the wild type allele. OBJECTIVES: To determine the presence of XMRV in non-familial prostate cancer samples. STUDY DESIGN: RNA from prostate tissue was analyzed for XMRV using nested RT-PCR. In all samples, RNase L (R462Q) genotyping was performed using an allele-specific PCR. RESULTS: XMRV-specific sequences were detected in one of 105 tissue samples from non-familial prostate cancer patients and from one of 70 tissue samples from men without prostate cancer. The two XMRV-positive patients were wild type or heterozygous for the R462Q mutation and thus carried at least one fully functional RNase L allele. CONCLUSIONS: XMRV was rarely detected in non-familial prostate cancer samples from Northern European patients. The homozygous mutation R462Q (QQ) was significantly underrepresented (
