Vitamin D3 status and polymorphisms of vitamin D receptor genes among cohort of Egyptian children with autism

BACKGROUND: The specific aetiology of autism spectrum disorder (ASD) is still unclear. We aimed to evaluate the potential association between three vitamin D receptor single nucleotide polymorphisms (VDR-SNPs) [ApaI (rs7975232), TaqI (rs 731236), and BsmI (rs1544410)] with susceptibility and severity of autism. METHODS: The current research involved 136 Egyptian children grouped into 86 autistic children, compared to 50 controls. In addition to the clinical evaluations of patients using Childhood Autism Rating Scale (CARS), EEG records were made. ELISA assays were performed for serum vitamin D3. The detection of VDR-SNPs by restriction fragment length polymorphisms was performed using polymerase chain reaction [RFLP-PCR]. RESULTS: Autistic males were 80.2%. The serum vitamin D3 levels in autistic children were significantly lower (15.3 ng/mL +/- 3.8) vs. the controls (31.5 +/- 6.75), P<0.05. Significant associations of both A allele at position rs7975232 and G allele at position rs1544410 of the VDR gene with increased incidence of autism among Egyptian children were observed (OR 2.14, 95% CI: 1.05- 2.96, P= 0.03) and (OR 1.95, 95% CI: 0.62 -3.57, P= 0.000). CONCLUSIONS: By altering the functionality of vitamin D3 metabolism, genetic polymorphisms in rs7975232 and rs1544410 of VDR may be associated with the development of autism among Egyptian children.