Major CYP450 Polymorphism among Saudi Patients

Background: Cytochrome P450 (CYP) contributes to a huge collection of medicinal products' Phase I metabolization. We aimed to summarize and investigate the current evidence regarding the frequency of CYP2D6, CYP2C9, CYP2C19, and MDR1 in Saudi Arabia. Methods: A computerized search in four databases was done using the relevant keywords. The screening process was done in two steps; title and abstract screening and full-text screening. Data of demographic and characteristics of included studies and patients were extracted and tabulated. Results: Ten studies were eligible for our criteria and were included in this systematic review. The age of participants ranged between 17-65 years. Only two subjects showed PM phenotype of CYP2C19 in the Saudi population. The most frequent alleles were CYP2C19*1 (62.9%), CYP2C19*2 (11.2%-32%), and CYP2C19*17 (25.7%). The CYP2C19 m1 was observed in 97 cases of extensive metabolizing (EM) phenotype CYP2C19. Concerning the CYP2C9, the most frequent alleles were CYP2C9*1 and CYP2C9*2, and the most frequent genotype was CYP2C9*1*1. The CYP2D6*41 allele and C1236T MDR1 were the most frequent allele in this population. Conclusion: The current evidence suggests that Saudi resembled European in the frequency of CYP2C19, Caucasians in both the incidence of CYP2C9 and CYP2C19 m1 , and the absence of CYP2C19 m2 . The CYP2D6*41 allele frequency in Saudi is relatively high. We recommend further research to evaluate the basic and clinical relevance of gene polymorphism in such ethnicity.