A genetic test for autism spectrum disorders?
Autism spectrum disorders (ASD) are an increasingly diagnosed group of neurodevelopmental disorders. Although heritability suggests a strong genetic component, efforts to identify genes involved have had disappointing results, and the difference in disease state between identical (monozygotic) twins points to a potential role for epigenetic factors. Two new studies have found a significant correlation between DNA methylation (DNAm) patterns and ASD traits. Wong et al. performed a genome-wide analysis of DNAm in a sample of 50 monozygotic twin pairs sampled from a representative population cohort that included twins discordant and concordant for ASD, ASD-associated traits and no autistic phenotype [1]. Numerous differentially methylated regions associated with ASD were identified and significant correlations between DNAm and quantitatively measured autistic trait scores were reported. Ladd-Acosta et al. examined DNAm in post-mortem brain tissue from 19 autism cases and 21 unrelated controls. Over 485 000 CpG loci were measured across a diverse set of functionally relevant genomic regions and four genome-wide significant differentially methylated regions were identified [2].
1. Wong et al. Mol Psychiatry 2013; doi: 10.1038/mp.2013.114 (www.nature.com/mp/journal/vaop/ncurrent/full/mp201341a.html).
2. Ladd-Acosta et al. Mol Psychiatry 2013; doi: 10.1038/mp.2013.114 (www.nature.com/mp/journal/vaop/ncurrent/full/mp2013114a.htm).
