COLD SPRING HARBOR, N.Y., Sept. 22 (UPI) -- Researchers found that rare mutations of a set of genes could be responsible for roughly half of all autism spectrum disorder, or ASD, cases. The "spontaneous" genetic mutations, researchers said, most likely happen to genes that are essential for normal brain development.
The new theory differs from a commonly held one that ASD is caused by a combination of genetic mutations that are harmless individually but when combined cause the disorder. Instead, researchers say mutations present in a germ cell or fertilized egg can result in ASD.