Results of a genome-wide linkage analysis in prostate cancer families ascertained through the ACTANE consortium

BACKGROUND. The aggregation of prostate cancer within families suggests a major inherited component to the disease. Genetic linkage studies have identified several chromosomal regions that may contain prostate cancer susceptibility loci, but none has been definitively implicated. METHODS. We performed a genome-wide linkage search based on 64 families, 63 with at least 3 cases of prostate cancer, ascertained in five countries. The majority of cases from these centers presented with clinically detected disease. Four hundred and one polymorphic markers were typed in 268 individuals. Multipoint heterogeneity analysis was conducted under three models of susceptibility; non-parametric analyses were also performed. RESULTS. Some weak evidence of linkage, under at least one of the genetic models, was observed to markers on chromosomes 2 (heterogeneity LOD (HLOD) = 1.15, P = 0.021), 3 (HLOD = 1.25, P = 0.016), 4 (HLOD = 1.28, P = 0.015), 5 (HLOD = 1.20, P = 0.019), 6 (HLOD = 1.41, P = 0.011), and 11 (HLOD = 1.24, P = 0.018), and in two regions on chromosome 18 (HLOD = 1.40, P = 0.011 and HLOD = 1.34, P = 0.013). There were no HLOD scores greater than 1.5 under any model, and no locus would be predicted to explain more than half of the genetic effect. No evidence in favor of linkage to previously suggested regions on chromosomes 1, 8,17, 20, or X was found. CONCLUSIONS. Genetic susceptibility to prostate cancer is likely to be controlled by many loci, with no single gene explaining a large fraction of the familial risk. Pooling of results from all available genome scans is likely to be required to obtain definitive linkage results.