Harmful mutations in MeCP2 don’t always lead to Rett syndrome, and the syndrome can result from mutations in other genes, according to a study published 26 June in the Journal of Molecular Diagnostics.

The genomes of people who have both autism and intellectual disability have more regions that may harbor recessive mutations than those of their unaffected siblings, according to a study published 11 July in the American Journal of Human Genetics.

Understanding the basis of sexual dimorphism in autism may not only inform our treatment of this condition, but may translate to therapies for many other mental illnesses, say Nirao Shah and Devanand Manoli.

Although thousands of candidate genes are linked to autism, many function together in just a few common pathways, according to a network analysis published in the June issue of PLoS Genetics. 

The first sizable study to use whole-genome sequencing to investigate autism has shown its mettle, revealing new mutations and candidate genes for the disorder, according to a report published 11 July in the American Journal of Human Genetics.

Males, but not females, with neurodevelopmental disorders such as autism are more likely to have deletions or duplications in the 16p13.11 chromosomal region than controls are, according to a study published 18 April in PLoS One.

Deletions in neurexin-1, a candidate gene for autism, may cause intellectual disability, speech delays, seizures, poor muscle tone and unusual facial features, according to two studies published in the past two months.

Intellectual disability, autism, epilepsy and schizophrenia should be considered part of a spectrum of developmental brain dysfunction, says David Ledbetter.

Two large Scandinavian studies published in March, which together include more than 10,000 children with autism, add to a growing body of research suggesting that older parents are at an increased risk of having children with autism.

A comparison of autism-like behaviors in nearly 10,000 pairs of fraternal twins suggests that girls are somehow protected from the disorder. The findings, published 19 February in the Proceedings of the National Academy of Sciences, may partly explain why autism is four times more common in boys than girls.