Editor—Prostate cancer is the second most common cause of male cancer mortality in the UK.1 Current indications are that like many common cancers, prostate cancer has an inherited component.2 Segregation analysis has led to the proposed model of at least one highly penetrant, dominant gene (with an estimated 88% penetrance for prostate cancer by the age of 85 in the highly susceptible population). Such a gene or genes would account for an estimated 43% of cases diagnosed at less than 55 years.2

One prostate cancer susceptibility locus (HPC1) has been reported on 1q24-253 and confirmed by Cooney et al 4 and Gronberg et al. 5 Latest estimates suggest that this locus would only account for 4% of families overall in the UK (upper 95% confidence interval (CI) limit of 31%).6 Another locus has been reported on 1q42.2-43 after a genome wide search of 47 French and German families.7 This locus is estimated to explain 50% of these families and appears to be distinct from theHPC1 locus as the two are estimated to be 60 cM apart. Confirmatory studies of this second locus have not yet been reported. A third locus has been reported. This locus, situated on the X chromosome, is estimated to explain approximately 16% of the families studied (including the families which were first typed to map the 1q24 locus).8 The heterogeneity lod score for linkage to this locus is 3.85 with the strongest evidence being a locus in proximity to the markers DXS297 and DXS1200.

While linkage studies have not identified chromosome 10 as the site of a predisposing gene, the long arm of chromosome 10 is the fourth commonest region showing loss of heterozygosity (LOH) in sporadic prostate cancers after 7q, 8p, and 16q.9 Deletion …