Autism

by Susan Williams

A new study at the University of Washington Medical School and Autism Center has found a link between genetic factors and autism. After nearly a decade of research, scientists at the university have found evidence that six major genes contribute to the development of autism; while up to thirty other genes have a lesser effect on the symptoms of autism. The findings were reported in the August online edition of the journal Molecular Psychiatry.

The study also provides new evidence to support the idea that multiple genes contribute to the development of autism. Scientists believe that individuals who inherit a greater number of these "susceptibility" genes may be more likely to develop a more severe case of autism.

Researchers have long suspected that genetics played a significant role in autism, as past clinical studies had found that identical twins, which have the same DNA, demonstrated higher rates of autism than did fraternal twins. Additionally, the researchers found two genetic subtypes of autism: male versus female, and early-onset versus late-onset. The fact that different genes may be responsible for causing autism in boys than in girls may help explain why the condition is more common in boys.

To reach these conclusions, the scientists studied the DNA of 223 families that had at least two children with autism, Pervasive Developmental Disorders, or Asperger's Syndrome, a less-severe form on the autism spectrum. Further studies will likely lead to the ability to test infants for those specific genes, which will allow for early intervention before the disease becomes severely debilitating. Researchers hope that this information will lead to a better understanding of the disorder, its diagnosis, and its treatment.

The ongoing research is part of the National Institute of Child Health and Human Development Collaborative Program of Excellence in Autism. Families who have more than one child of any age with an autism spectrum disorder who are interested in participating in the university's genetics study can call toll free at 1- 800-994-9701.