Autism. In recent years, scientists have identified rare genetic mutations that cause autism in young children. They have likewise found a large number of genetic changes that increase the risk that a child will develop this disorder.
Albert Kim
In recent years, scientists have identified rare genetic mutations that cause autism in young children. They have likewise found a large number of genetic changes that increase the risk that a child will develop this disorder. However, fewer than 20 percent of those with an Autism Spectrum Disorder (ASD) show identifiable gene defects directly related to the disease (Akbarian). A new study provides strong evidence that, in some cases, the development of autism actually manipulates gene expression inside a cell. These developments of autism stem not from mutations in the genes themselves but from problems with proteins that help control gene expression inside a cell.
Epigenetics is the study of gene regulation and organization that occurs independent of changes in a gene’s code, or DNA sequence. Like DNA mutations, these epigenetic changes can be inherited and run in families for generations. But these mutations can also be caused by exposure to chemicals, lack of crucial nutrients, and other many possible stresses inflicted on the individual. Histone methylation is an epigenetic function that affects brain development. It modifies certain amino acids in highly alkaline proteins; histone methylation turns the genes “on,” allowing transcription factors and other proteins access to the DNA, or “off,” denying them access. The vast majority of genes in a given cell remain off, or inactive, at any given time. As in other parts of the body, normal brain development and function depend on the right genetic tasks performing at the right time. Thus, if histone methylation occurs abnormally, disrupting normal gene expression in cells, there is an increased risk of autism.