Aim: To detect early-life environmental factors leading to DNA methylation changes of autism spectrum disorder (ASD)-related genes in young ASD females and reveal epigenetic biomarkers of disease severity. Materials & methods: We investigated blood methylation levels of MECP2, OXTR, BDNF, RELN, BCL2, EN2 and HTR1A genes in 42 ASD females. Results: Maternal gestational weight gain correlated with BDNF methylation levels (Bonferroni-corrected p = 0.034), and lack of folic acid supplementation at periconception resulted in higher disease severity in the ASD children (Bonferroni-corrected p = 0.048). RELN methylation levels were inversely correlated with disease severity (Bonferroni corrected p = 0.042). Conclusion: The present study revealed gene-environment interactions and potential epigenetic biomarkers of disease severity in ASD females.
Keywords: BDNF; DNA methylation; MECP2; RELN; autism spectrum disorder; biomarker; epigenetics; female; folic acid.
Early-life maternal factors can leave marks on the DNA of the developing fetus, including changes in DNA methylation that regulate gene expression levels. These marks can pose an increased risk for several diseases, such as autism spectrum disorder (ASD) and other developmental disorders. In the present study, we searched for links between early-life maternal factors and the methylation levels of ASD-related genes in blood DNA samples of young ASD diagnosed females. We found that high maternal gestational weight gain resulted in increased methylation levels of the BDNF gene, one of the most important genes for brain development. Moreover, lack of maternal folic acid supplementation and low RELN methylation levels resulted in higher disease severity in ASD females.