Genetic mutation ups schizophrenia risk

COLD SPRING HARBOR, N.Y., Oct. 26 (UPI) -- A U.S.-led team of geneticists says it has identified a mutation on human chromosome 16 that substantially increases the risk of developing schizophrenia.

Cold Spring Harbor Laboratory geneticist Jonathan Sebat, who led the study, said the mutation is a copy number variant -- an area of the genome where the number of copies of genes differs between individuals. The newly discovered copy number variant is located in a region referred to by scientists as 16p11.2. By studying the genomes of 4,551 patients and 6,391 healthy individuals, Sebat's team determined having one extra copy of that region is associated with schizophrenia.

"In the general population this duplication is quite rare, occurring in roughly one in 5,000 persons," Sebat said. "But for people that carry the extra copy, the risk of developing schizophrenia is increased by more than eight-fold."

Studies by other groups have shown losing one copy of 16p11.2 confers high risk of autism and other developmental disorders in children. Taken together, the researchers said the studies suggest some genes are shared between schizophrenia and autism.

The findings are detailed in the early online edition of the journal Nature Genetics and will appear in the journal's November print issue.