Background: colorectal cancer (CRC) is the third most common type of cancers and the fourth leading causeof death worldwide. In Saudi Arabia, CRC accounts for 8.5% of all tumors; it ranks first among all cancersin males and third among females. The aim of this study was to link between different PARP-1 mutations andrisk of CRC in Saudi population and to determine common variants of PARP-1 in Saudi CRC patients andnormal individuals. Materials and
Methods: DNA samples were isolated from fifty CRC patients and from acomparable number of control subjects then sequenced to detect different variations present in exons 3, 17, and21 of the PARP-1 gene. Results and
Conclusions: When comparing the genotype and allele frequencies of alldetected SNPs in CRC patients with those in controls, we found none were significantly different for all variantseven the most common SNP in PARP-1 gene (Val762Ala). However, two novel alterations in exon 21 were foundto be associated with increased risk of CRC. The variants identified as (1) Lys933Asn [p-value 0.0318] and (2)Lys945Asn [p-value 0.0257]. Our results suggest that PARP-1 Lys933Asn and Lys945Asn alterations could beassociated with increased risk of CRC in the Saudi population.