Autism could be inherited

A new study of 2 million children from 5 countries has determined that one’s inherited genetics contribute nearly 80% of the risk for developing autism spectrum disorders (ASDs), according to Swedish researchers. The surprising results of population data from Australia, Denmark, Finland, Israel, and Sweden were just published in JAMA Psychiatry.

The study population was comprised of children born between January 1, 1998, and December 31, 2011, and researchers followed them until they reached age 16 years. In this entire group, 22,156 children were diagnosed with ASDs. After examining genetic outcomes among family members, maternal effects, and environments, the researchers estimated the heritability of autism to be approximately 80%. There were only modest differences in the heritably rate among the 5 countries.

In a companion editorial, several autism and psychiatry experts said years of research have disproportionately implicated environmental factors and parental influences as affecting the incidence of autism.

The new study authors suggest it’s now time to recognize how family history might contribute heavily to a child’s risk of developing ASD, and to be observant for early signs of autism as they present so that interventions can begin as early as age 2 years. Expectant parents who are aware of a family history of autism might consider genetic counseling, one researcher noted.

The researchers also point out that more work needs to be done to identify which specific genes, alone or in combination with potential environmental and familial factors, contribute to autism and in which specific ways.