Among autistic children with no family history of ASD, researchers uncovered 49 gene mutations disrupting a pathway that modifies chromatin and regulates genes in the brain and nervous system. Various changes in this pathway contribute to children developing autism in different ways. Many different forms of autism exist at the molecular level, making ASD an umbrella disorder with many root causes. Conversely, many intellectual, social and mental disorders share common mutations. Divisions clinicians make among these disorders may not translate into molecular differences.