Genetics of Autism: Escalating Complexities

A rare mutation explained about 1% of autism cases in three studies, but de novo mutation and inheritance patterns preclude easy clinical applications.

Autism spectrum disorders (autism) are strongly genetic and highly variable clinically. Although autism can be associated with many single Mendelian and a few mitochondrial gene mutations, each of these mutations is rare. In unstigmatized individuals without medical problems or overall intellectual deficiency (“idiopathic” autism), inheritance is rarely straightforwardly Mendelian. In three new reports, different researcher groups used genome-wide scans to uncover single-stranded DNA deletions or duplications called copy number variations (CNVs), ranging from one to several hundred or more genes in length and invisible to cytogenetics, in individuals with autism.

Weiss and colleagues compared DNA from three databases including almost 2000 in…

Reviewing Author

Isabelle Rapin, MD