People with attention deficit hyperactivity disorder may carry certain rare, harmful mutations in many of the same genes as people with autism.

In autism research, as in other fields, small sample sizes can lead to false findings. The size of the sample needed for statistical significance depends on the type of study.

People who have a mutation linked to autism plus a second genetic glitch tend to have more severe symptoms than those with the mutation alone.

Two new online resources help researchers predict how mutations alter protein structure.

A single gene, OTUD7A, may account for most of the features seen in people missing a segment of chromosome 15 known as 15q13.3.

Mutations that appear in only some of the body’s cells contribute to autism in about 4 percent of people with the condition.