H-ras-1 restriction fragment length polymorphism in normal individuals and oral cancer patients in India

Restriction fragment length polymorphism (RFLP) of the human H-ras-l gene has been indicated as a marker for detection of individuals at high risk of cancer. We have investigated the association of RFLP at the H-ras-l locus and susceptibility to oral cancer by Southern hybridization analysis in 77 primary oral tumors and 99 healthy donors. The frequency distribution of the Bum HI fragments of H-ras-l revealed homozygous or heterozygous alleles in the two sub-populations. The heterozygous genotype occurred more frequently in the normal subjects (53%) as compared to the cancer patients (36%). Four common alleles Cl to C4, were noted predominantly in both groups, with rare alleles detected at a lower frequency. The common allele with 7.6 kb BamHI fragment was significantly higher in normals (10%) than in the tumor population (4%) (P≤0.05). However, a similar distribution of rare alleles in both groups indicated that the presence of rare alleles is not indicative of predisposition to oral cancer