Vitamin D Receptor Polymorphisms Associated with Autism Spectrum Disorder

Area of Science:

• Genetics
• Neuroscience
• Endocrinology

Background:

• Vitamin D possesses anti-inflammatory properties and may influence autism spectrum disorder (ASD) pathogenesis.
• Vitamin D biological activity is mediated by the Vitamin D Receptor (VDR), influenced by VDR gene polymorphisms.

Purpose of the Study:

• To investigate the association between VDR gene polymorphisms (FokI, BsmI, ApaI, TaqI) and ASD in Italian families.
• To explore the correlation between VDR genotypes and ASD-related behaviors, including hyperactivity.

Main Methods:

• Genotyping of VDR FokI, BsmI, ApaI, and TaqI Single Nucleotide Polymorphisms (SNPs) in 100 Italian families with ASD children.
• Statistical analysis including genotype and allele distribution comparison, Transmission Disequilibrium Test (TDT), and haplotype analysis.

Main Results:

• FokI genotype distribution was significantly different in ASD children and their mothers compared to healthy controls.
• A protective effect was observed for the FokI (C) allele and a specific (CCAG) haplotype, which were less frequent in ASD children.
• The FokI (T) allele showed a gene-dose association with higher ASD severity scores and hyperactivity in ASD children.

Conclusions:

• VDR gene polymorphisms, particularly FokI, are associated with ASD susceptibility and behavioral phenotypes.
• The FokI (C) allele and the CCAG haplotype may confer a protective effect against ASD.
• Reduced VDR biological activity due to specific polymorphisms might contribute to ASD pathogenesis and inflammation. Vitamin D supplementation warrants consideration for ASD management.