Increased frequency of specific alleles of the c-Ha-ras gene in Japanese cancer patients.

We have examined the c-Ha-ras locus in 145 cancer patients of a mixed group and 164 normal individuals in Japan for restriction fragment length polymorphisms and compared the allele distributions in normal and cancer populations. The c-Ha-ras gene is highly polymorphic in Japanese as previously reported in Caucasians. Two rare alleles were found to be present with increased frequencies in Japanese cancer patients. These results suggest that genotype analysis of the c-Ha-ras gene could be used to detect cancer-prone individuals.