Boys with autism have smaller heads, are shorter and weigh less at birth than typical children do — but all that changes by age 3.

Mutations in the gene PTEN that are tied to autism may be less harmful than those linked to a syndrome characterized by benign tumors.

Male monkeys that avoid touching, grooming or playing with others have low brain levels of the hormone vasopressin.

The activity of a set of proteins in the blood may distinguish people with autism from those without the condition.

Decoding distortions in the brain’s largest nerve tract could lay bare basic problems with long-range neural connections in autism.

Researchers are beginning to understand how mutations in a cancer-linked pathway called WNT contribute to autism.

A comprehensive catalog of the genes that show ties to both autism and cancer highlights the role of cell growth in both conditions.