Among the younger siblings of children with autism who do not have the disorder themselves, more than one-quarter show developmental delays at their first birthday, according to a study published in April.

Mutations in a gene associated with DNA packaging may lead to autism and intellectual disability, suggests a study published 16 February in Nature Genetics.

Many characteristics of Phelan-McDermid syndrome — an autism-linked disorder arising from abnormalities at the tip of chromosome 22q13 — change as individuals age.

A widely used screen for autism identifies only one-third of children at 18 months who are later diagnosed with the disorder, reports a large Norwegian study published 18 February in Paediatric and Perinatal Epidemiology.

A teenager with fragile X syndrome carries a rare mutation that changes a single amino acid in the FMRP protein, researchers reported 22 January in the European Journal of Human Genetics.

It takes more mutations to trigger autism in women than in men, which may explain why men are four times more likely to have the disorder, according to a study published 26 February in the American Journal of Human Genetics.

Babies later diagnosed with autism are slow to start babbling and do less of it once they get started than controls do, reports a study published 31 January in the Journal of Autism and Developmental Disorders.

An updated version of a test that detects autism symptoms in toddlers is shorter, simpler and more accurate than its predecessor, making it easier for pediatricians to identify children in need of further testing, reports a study published in the January issue of Pediatrics.

Children with autism develop interactive skills late and many lose at least one skill by 3 years of age, says a study published in November.

Different combinations of genes located in an autism-linked section of chromosome 22 may modulate various symptoms, such as speech problems, large head size and low muscle tone, researchers reported 17 October in Genetics in Medicine.