Vitamin D Receptor Gene Polymorphism FokI (rs2228570) among Egyptian Children with Type 1 Diabetes Mellitus

Background: T1DM is an autoimmune disease marked by pancreatic beta-cell destruction, causing lifelong insulin dependence. While often diagnosed in childhood, 25% of cases occur in adults. Egypt ranks among top ten countries globally for diabetes prevalence (ages 20–79). Human VDR gene has over 14 polymorphisms; among them, FokI (rs2228570) has been studied for its potential role in T1DM, as vitamin D signaling influences insulin receptor gene expression through VDR interactions.
Objective: This study aims to investigate the association between the VDR gene FokI (rs2228570) polymorphism and susceptibility to T1DM among Egyptian children.
Subjects and methods: This case-control investigation assessed association between FokI (rs2228570) polymorphism and T1DM in 200 Egyptian children (100 with T1DM and 100 healthy controls) aged 1 month to 18 years. Participants were recruited from Mansoura University Children’s Hospital between October 2023 and September 2024. Genotyping analysis was carried out utilizing real-time PCR technique.
Results: The mean ages of cases and controls were 9.48 ± 3.22 and 8.85 ± 3.71 years respectively (p=0.216) with comparable sex distributions (p=0.322). Genotype frequencies (GG/AG/AA) were 51%/45%/4% in cases and 59%/37%/4% in controls (p>0.05). Allele distributions showed no substantial variations (G: 73.5% vs. 77.5%; A: 26.5% vs. 22.5%; p>0.05). Both groups were in Hardy-Weinberg equilibrium.
Conclusion: FokI (rs2228570) polymorphism was not substantially correlated with T1DM in Egyptian children, indicating it may not play a major role in genetic susceptibility to T1DM in this population.