Autism, a developmental disorder, may more likely be carried by mothers and dependent on parental age, according to U.S. researchers.
Researchers at Cold Spring Harbor Laboratory and Albert Einstein College of Medicine analyzing the incidence of autism found a previously unrecognized pattern pointing to a spontaneous germ-line mutation model of disease acquisition.
The study, published in the Proceedings of the National Academy of Sciences, indicates parents, especially women -- who acquire the mutation but do not exhibit severe symptoms of the disorder -- have a 50 percent chance of passing the mutation on to their children. Sons often show the most severe symptoms.
"The fact that germ-line mutations increase with age places older parents at a higher risk of having children with autism, explaining a pattern that has been recently observed," study co-author Michael Wigler, of CSHL, said in a statement.
The model proposes two risk classes. One is sporadic or low risk autism -- the more common form -- caused by spontaneous germ-line mutation. The children, mostly female, who receive such a mutation but do not display the disorder, are the source of the other risk class -- high risk families. Boys in high risk families may account for a quarter of autism. according to the study.
Copyright 2007 by UPI
