Spontaneous gene glitches linked to autism risk with older dads

from National Institutes of health NIH

Non-inherited mutations spotlight role of environment – NIH-supported study, consortium

Researchers have turned up a new clue to the workings of a possible environmental factor in autism spectrum disorders (ASDs): fathers were four times more likely than mothers to transmit tiny, spontaneous mutations to their children with the disorders. Moreover, the number of such transmitted genetic glitches increased with paternal age. The discovery may help to explain earlier evidence linking autism risk to older fathers.

The results are among several from a trio of new studies, supported in part by the National Institutes of Health, finding that such sequence changes in parts of genes that code for proteins play a significant role in ASDs. One of the studies determined that having such glitches boosts a child’s risk of developing autism five to 20 fold.

Taken together, the three studies represent the largest effort of its kind, drawing upon samples from 549 families to maximize statistical power. They reveal sporadic mutations widely distributed across the genome, sometimes conferring risk and sometimes not. While the changes identified don’t account for most cases of illness, they are providing clues to the biology of what are likely multiple syndromes along the autism spectrum.

"These results confirm that it’s not necessarily the size of a genetic anomaly that confers risk, but its location – specifically in biochemical pathways involved in brain development and neural connections. Ultimately, it’s this kind of knowledge that will yield potential targets for new treatments," explained Thomas, R. Insel, M.D., director of the NIH’s National Institute of Mental Health (NIMH), which funded one of the studies and fostered development of the Autism Sequencing Consortium, of which all three groups are members.

The mission of the NIMH is to transform the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery and cure. For more information, visit www.nimh.nih.gov.

The activities described in this release are being funded through the American Recovery and Reinvestment Act (ARRA). More information about NIH’s ARRA grant funding opportunities can be found at http://grants.nih.gov/recovery/. To track the progress of HHS activities funded through the ARRA, visit www.hhs.gov/recovery. To track all federal funds provided through the ARRA, visit www.recovery.gov.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.
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