Researchers have determined the deletion of specific genes on chromosome 17 can increase the risk for autism spectrum disorders (ASD) and schizophrenia nearly 14-fold.

The research, an international collaboration led by Emory University scientists, will be published in the American Journal of Human Genetics.

A mutation of one of the genes in the deleted interval already is a known cause of renal cysts and diabetes syndrome (RCAD). Scientists have known that autism and schizophrenia are also strongly influenced by genetic mutations.

The finding resulted from cytogenetic array analysis in patients with neurodevelopmental disorders referred for clinical testing.

Researchers detected a recurrent deletion in 24 patients out of more than 23,000 patients with ASD, developmental delay, intellectual disability, or schizophrenia.

This deletion was not present in any of 52,448 control individuals.

“We calculate a minimum odds ratio of 13.58 for this sample,” says David H. Ledbetter, Ph.D., a lead author of the study, “meaning that someone with this deletion is at least 13.58 times more likely to develop ASD or schizophrenia than is someone lacking this genetic variation.”

The deleted region (17q12) contains 15 genes, including HNF1B, the gene associated with RCAD. Patients with RCAD also often have neurodevelopmental disorders.

A number of the ASD patients in the study were found to have kidney disease or diabetes as well.

“We have uncovered a copy number variation that confers a very high risk for ASD, schizophrenia, and neurodevelopmental disorders,” says Emory University researcher Daniel Moreno-De-Luca, M.D.

“This is significant, because the 17q12 deletion is among the 10 most frequent pathogenic recurrent genomic deletions identified in children with unexplained neurodevelopment impairments.

“We believe it also may increase risk for other psychiatric conditions such as bipolar disorder,” he says.

Source: Emory University