A mutated gene’s link to a rare form of obsessive compulsive disorder (OCD) is the strongest proof yet that neuropsychiatric disease can result from a malformed neuronal protein.

In studies published last October and August in Molecular Psychiatry and Molecular Pharmacology, researchers at Yale and the National Institute of Mental Health found that a rare form of OCD is associated with a mutation in the serotonin transporter gene that disrupts the normal regulation of transport.

“There are not a lot of established connections between genes and behavior,” said Gary Rudnick, Ph.D., professor of pharmacology, who conducted the research with Fusun Kilic, Ph.D., of the University of Arkansas for Medical Sciences. “Our finding focuses on the role of the serotonin transporter in mood and behavior and ties it to a specific behavioral disorder.”

The researchers found in two unrelated families a gene mutation that increases up-take of serotonin by the transporter. Further study could lead to a better understanding of how OCD develops and how medications might affect the serotonin transporter.