They found genetic variations in one gene that occur with greater frequency in individuals with autism disease and their family members. This gene codes for a protein that is involved in production of ATP, the molecule that acts as fuel providing the energy cells need to function. The mutations identified lead to production of excessive amounts of this protein. Dysfunction of this gene could lead to irregularities in the production of molecules that fuel the cells. Since brain cells consume large amounts of energy even minor disruptions in production of such fuel can significantly affect the cells ability to function normally.

The variants of this gene found in this study appear to be very common. In and of themselves they do not cause autism, nor do individuals with these variants necessarily have any symptoms. Having one of these variants appears to approximately double an individuals risk for the disorder, but it is an accumulation of genetic factors that cause the disease, said Dr. Buxbaum. So, our current challenge is to identify more of these genes.