Nucleotide excision repair gene XPD exon 23 gene polymorphism among Saudi healthy population: a comparative frequency analysis across healthy population worldwide

BACKGROUND: DNA damage poses a constant threat to genome integrity, and deficiencies in DNA repair mechanisms are associated with an increased risk of cancer. The XPD gene plays a crucial role in the nucleotide excision repair (NER) pathway. According to earlier research, the frequency of the XPD exon 23 A>C gene polymorphism varies throughout ethnic groups. This study aims to determine the prevalence of the XPD exon 23 A>C polymorphism in the healthy Saudi population and to compare this frequency with other ethnic group worldwide. METHODS: The PubMed (Medline), Google Scholar and Elsevier database was searched for epidemiological studies focusing on various ethnic groups worldwide. The genotype and allele frequencies of XPD exon 23 A>C were identified. The statistical software SPSS 21 was used for all statistical analysis. RESULTS: The frequency of the minor allele (C) of the XPD exon 23 polymorphism in the Saudi population was observed to be higher 55% compared to all other global ethnic populations, including Bangladesh (27%), Belarus (42%), Belgium (34%), Brazil (30%), Canada (40%), India (32%), Italy (42%), Malaysia (15%), Norway (34%), Pakistan (23%), Romania (32%), Sudan (15%), Sweden (38%), Thailand (12%), Türkiye (41%), the UK (39%), and the USA (38%). In Iran, the frequency of the variant allele (C) was 52%, which is near to that of the Saudi Arabian population. The lowest frequency (7%) was observed in the Chinese population. Significant differences in the frequency distribution of the variant genotype were observed in most of the studied worldwide populations compared to the Saudi Arabian population. However, the frequency distribution of the variant genotype in Iran showed no significant difference (P=0.483) when compared to the Saudi Arabian population. CONCLUSIONS: This study suggests that the frequency of the NER XPD exon 23 A>C gene polymorphism in the Saudi population differs from other ethnic groups. This information could support high-risk screening for those exposed to environmental carcinogens and may contribute to understanding population specific genetic susceptibility to cancer among Saudi population.