New Evidence of Genetic Links between Autism and Related Impairments

Date: 
October 31, 2013
Researchers study families affected by autism and associated disorders; findings could guide development of personalized treatments

Lorenzo Miodus-Santini, now 11, was never a big talker. As an infant he didn't babble or coo. When he began to speak as a toddler, he’d learn one word but forget another. At 13 months, he was diagnosed with autism spectrum disorder (ASD).

Lorenzo’s older brother, Christian, doesn’t have autism but likewise struggles with language. Christian has difficulty reading, processing spoken words and speaking clearly. Doctors gave him the diagnosis of specific language impairment.

Both boys were part of a research study that found evidence of genetic links between autism and the impairments that often accompany it. The findings appear online in the American Journal of Psychiatry.

Specifically, the researchers found genetic changes in a narrow region of two chromosomes – 15q23-26 and 16p12 – that increased risk for both autism and language impairment. Such linkages may help explain why about half of those with ASD also have some degree of language impairment. In this case, some individuals with the gene changes developed autism, others language impairment, and still others developed both. 

“Research such as this helps us understand the mechanisms that underlie autism as well as the associated impairments that affect many but not all individuals on the spectrum,” comments geneticist Andy Shih, Autism Speaks senior vice president for scientific affairs. (Dr. Shih was not involved in the study.) This, in turn, could lead to the identification of biological pathways that might respond to new treatments.

Families affected by autism share related difficulties
The study was led by scientists at Rutgers University, in New Jersey, and Nationwide Children’s Hospital, in Columbus, Ohio. Nationwide Children’s is a member of Autism Speaks Autism Treatment Network. The investigators performed extensive in-home testing on 79 families with one child with autism and at least one other with language impairment. In addition to genetic testing, family members completed a battery of tests that assess grammar, vocabulary and language processing. The researchers found additional evidence of genetic links between autism and obsessive-compulsive disorder. As with language impairment, this disorder appeared with higher than normal frequency in family members who did not have autism.

Next, the researchers hope to perform whole genome sequencing on the families to pinpoint the specific genes associated with these traits. 
 

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