Epigenetic Insights into Autism Spectrum Disorder: DNA Methylation Levels of , and in Korean Autism Spectrum Disorder Sibling Pairs.

OBJECTIVE

Previous research on autism spectrum disorder (ASD) in Koreans has primarily focused on genetic diversity because of its high heritability. However, the emerging recognition of transgenerational epigenetic changes has recently shifted research attention towards epigenetic perspectives.

METHODS

This study investigated the DNA methylation patterns of the promoter regions of candidate genes such as , , and in blood samples from ASD probands and their unaffected siblings. The analysis included 54 families (ASD proband group: 54; unaffected biological sibling group: 63). The diagnostic process involved screening the probands and their siblings for ASD based on the Diagnostic and Statistical Manual of Mental Disorders 5th edition. Intelligence, social ability, and medical history were thoroughly assessed using various scales and questionnaires. Genomic DNA from blood samples was analyzed using a methylation-sensitive quantitative polymerase chain reaction to examine the DNA methylation status of candidate genes.

RESULTS

Methylation levels in candidate gene promoter regions differed significantly between the proband and sibling groups for all candidate genes. Correlation analysis between the proband and sibling groups revealed strong and significant correlations in and methylation. Additionally, in the analysis of the relationship between DNA and ASD phenotypes, methylation correlated with social quotient in probands, and methylation was associated with nonverbal communication, and daily living skills as measured by the Korean Vineland Adaptive Behavior Scale. Notably, methylation was significantly associated with parental age at pregnancy.

CONCLUSION

This study proposes DNA methylation of , , and in peripheral blood samples is a potential epigenetic biomarker of ASD.