Individuals who carry a large and rare deletion on chromosome 16 that is associated with autism are likely to have developmental delays, be obese or both, according to two studies published last week in Nature.

Deletions or duplications of chromosomal segment 16p11.2 — previously reported as a key autism region — are seen in people with developmental delays and speech and behavioral problems, but not necessarily autism. That’s the finding from two large studies published last week of people carrying these rare genetic variations.

Variations linked to autism and schizophrenia crop up in people with a large variety of conditions, including bipolar disorder, seizures and obsessive-compulsive disorder, as well as in healthy people. This notion gained new support from unpublished data presented at the World Congress for Psychiatric Genetics in San Diego.