Formation of cognitive processes in children with autism. Part I. Epigenetic mechanisms

Abstract

   Autism and autism spectrum disorders are neuropsychiatric diseases that begin to appear in children under 3 years. Over the past decade, the number of children with autism spectrum disorders has increased more than in 10-fold and continues to grow, accounting for 1–2 % of the world’s population. Currently, the diagnosis of autism spectrum disorders is based only on clinical and behavioral tests, and there are no biological and genetic markers that could contribute to the early detection of this disorder. The review, based on the analysis of modern literature data about epigenetic mechanisms which associated with autism, examines the influence of the DNA methylation profile in the formation of cognitive impairment and the possibility of using genes and their methylation status as diagnostic biomarkers in children with autism spectrum disorders. Literature data analysis shows that disorders of attention, speed of information processing, working memory, learning are based on genetic and epigenetic (methylation) changes in the expression of many genes: BDNF, CAPS2, CNTNAP2, GABRB3, FMR1, FOXP1, GTF2I, HSD11B2, MECP2, NF2, NGF, NR3C1, OXTR, PAK2, RELN, SLC6A4, UBE3A, etc. Most of these genes undergo hypermethylation, reducing the expression of its proteins, which impairs the development and formation of the nervous system in autism. In contrast, other genes are associated with methylation and oxidative stress are hypomethylated in autism spectrum disorders. Assessing the expression levels and methylation status of these genes can serve as genetic and epigenetic biomarkers for the differentiation and diagnosis of clinical symptoms, autism spectrum disorders severity, and facilitate the development of new treatments and rehabilitation procedures.