New genetic clues uncovered in largest study of families with multiple children with autism

UCLA Health researchers have published the largest-ever study of families with at least two children with autism, uncovering new risk genes and providing new insights into how genetics influence whether someone develops autism spectrum disorder.

The new study, published July 28 in the Proceedings of the National Academy of Sciences, also provides genetic evidence that language delay and dysfunction should be reconsidered as a core component of autism.

Most genetic studies of autism have focused on families with one child affected by the neurodevelopmental disorder, sometimes excluding families with multiple affected children. As a result, few studies have examined the role of rare inherited variation or its interaction with the combined effect of multiple common genetic variations that contribute to the risk of developing autism.

“Study design is critical and not enough attention has been paid to studying families with more than one affected child,” said lead study author Dr. Daniel Geschwind, the Gordon and Virginia MacDonald Distinguished Professor of Human Genetics, Neurology and Psychiatry at UCLA.

Autism is highly heritable: It is estimated at least 50% of genetic risk is predicted by common genetic variation and another 15-20% is due to spontaneous mutations or predictable inheritance patterns. The remaining genetic risk is yet to be determined.

For this study, researchers performed whole genome sequencing in 4,551 individuals from 1,004 families with at least two children diagnosed with autism. This group included 1,836 children with autism and 418 children without an autism diagnosis.

Read more in UCLA Health