The present invention relates to PG1, a gene associated with prostate cancer. The invention provides polynucleotides including biallelic markers derived from PG1 and from flanking genomic regions. Primers hybridizing to these biallelic markers and regions flanking are also provided. This invention provides polynucleotides and methods suitable for genotyping a nucleic acid containing sample for one or more biallelic markers of the invention. Further, the invention provides methods to detect a statistical correlation between a biallelic marker allele and prostate cancer and between a haplotype and prostate cancer. The invention also relates to diagnostic methods of determining whether an individual is at risk for developing prostate cancer, and whether an individual suffers from prostate cancer as a result of a mutation in the PG1 gene.