Abstract
This study aims to assess the association of two single nucleotide polymorphisms (SNPs), G34A and C376T, in the ABCG2 gene with the risk of developing CRC. To the best of our knowledge, this is the first study that determined the role of genetic variations in the ABCG2 gene with the risk of CRC in Saudi Arabia. The gDNA was extracted from the blood of 58 CRC patients and 48 healthy subjects. The DNA sequencing was used to determine the distribution of genotypes. The results showed that CRC patients carried a heterozygous (GA) genotype for SNP G34A had a low risk of developing CRC (odds ratio=0.015, 95% CI [0.00-0.12]; risk ratio=0.35, 95% CI [0.25-0.12], P <0.0001). On the other hand, patients that carried a heterozygous (CT) genotype for SNP C376T had a high risk of developing CRC (odds ratio=13.83, 95% CI [4.31-44.38]; risk ratio=4.88, 95% CI [1.95-12.24], P <0.0001). In conclusion, the results indicated that a heterozygous (GA) genotype in SNP G34A may decrease the risk of CRC development, whereas, the heterozygous (CT) genotype in SNP C376T may increase the risk of CRC. The results may suggest a protective role of ABCG2 SNP G34A against CRC and a deleterious effect of ABCG2 SNP C376T for increasing the risk of CRC.