The chances of developing schizophrenia rise substantially for the small number of children who possess only one copy of a gene variant that regulates a crucial chemical messenger in the brain, according to a new finding of a long-term investigation.
A team led by psychiatrist Allan L. Reiss of Stanford University School of Medicine studied 24 children missing a small piece of DNA on chromosome 22. About 30 percent of youngsters with this deletion, which occurs in 1 in 4,000 births, eventually develop the severe mental disorder schizophrenia or related psychotic conditions. These children are also prone to other problems, including heart defects, cleft palate, and learning disorders.
Prior studies showed that people with this deletion lack one copy of the usual two copies of the COMT gene, which triggers production of a protein that breaks down the neurotransmitter dopamine. The protein comes mainly in two variants with contrasting dopamine-busting power, one w