Analysis of the Vitamin D Receptor (VDR) Start Codon Polymorphism (Rs2228570) in Hemodialysis Patients from Abidjan, Côte d’Ivoire

In patients with chronic kidney disease (CKD), particularly those undergoing hemodialysis, vitamin D deficiency is highly prevalent. Individual sensitivity to vitamin D can be influenced by genetic variations in the vitamin D receptor (VDR) gene. Among these, the rs2228570 polymorphism, located in exon 2 and commonly referred to as the FokI polymorphism, produces two protein isoforms with differing transcriptional activity. Although this polymorphism has been widely studied in other populations, data on its distribution in West African populations, particularly among individuals with altered vitamin D metabolism, such as hemodialysis patients, remain scarce. The aim of this study was to investigate the frequency of the rs2228570 (FokI) polymorphism in the VDR gene among hemodialysis patients in Abidjan, Côte d’Ivoire. In a cross-sectional study, genomic DNA from fifty adult patients with CKD were extracted from whole blood samples. The DNA region spanning the SNP of interest was amplified by PCR. The amplified DNA was subjected to the action of FokI restriction enzymes. Genotyping was performed by analysis of the length of restriction fragments by 3% agarose gel electrophoresis. The mean age of the study population was 40±17 years, with a sex ratio of 1.9. Genotyping was successfully performed in forty-three of the fifty patients included. Genotype and allele frequencies were calculated, and their distribution was assessed. The FF (CC) genotype was the most frequent (79%), followed by the Ff (CT) and ff (TT) genotypes at 16% and 5%, respectively. Our findings highlight a high frequency of the FF genotype of the VDR gene in hemodialysis patients in Abidjan. Future research is needed to investigate the functional impact of this genotype on vitamin D status and its potential clinical implications in this population.