Identification of KRAS gene codon 12 polymorphism in colorectal cancer patients at Mohammad Hoesin General Hospital Palembang

Colorectal cancer occurs due to neoplastic transformation of epithelial cells in the colon and rectum resulting from the accumulation of genetic and epigenetic aberrations. One of the genetic factors associated with colorectal cancer is KRAS gene polymorphism, which mostly occurs in codon 12. KRAS gene polymorphism leads to constitutional activation of KRAS protein effectors which will initiate signalling network to nucleus to increase cell proliferation, survival and differentiation. The aim of this study was to identify the KRAS gene codon 12 polymorphism in colorectal cancer patients at Mohammad Hoesin General Hospital Palembang. This study was a descriptive laboratory study with PCR–RFLP technique using BstNI enzyme on thirty patients with colorectal cancer. Wild type genotype (GG) of KRAS gene codon 12 found in 15 patients (50%), heterozygous mutant genotype (Gg) found in 12 patients (40%) and homozygous mutant genotype (gg) only found in 3 patients (10%). The G allele frequency was 70% and the g was 30%. The most common genotype found in colorectal cancer patients was GG genotype and most common alotype was G allele. KRAS gene polymorphism was found in half of the colorectal cancer patients, heterozygous mutant genotype (Gg) was more frequent then homozygous mutant genotype (gg).