Study characterizes epigenetic signatures of autism in brain tissue

November 7, 2011

Neurons in the prefrontal cortex of individuals with autism show changes at numerous sites across the genome, according to a study being published Online First by the Archives of General Psychiatry.

Autism spectrum disorders are a group of complex illnesses with different causes and origins. Neuronal dysfunction in the and other regions of the brain could contribute to the cognitive and behavioral defects in autism, according to background information in the article. Neurons are that send and receive within the body.

Hennady P. Shulha, Ph.D., of the University of Massachusetts Medical School, Worcester, Mass., and colleagues examined the postmortem brain tissue of 16 individuals diagnosed with autism spectrum disorder (average age 17.4 years; range 2 to 60 years) and 16 controls without autism (ranging in age from less than one year to 70 years). The tissue was obtained through the Autism Tissue Program.

The study searched, on a genome-wide scale, for genes that show an abnormal epigenetic signature – specifically histone methylation. Histones are small proteins attached to the DNA that control gene expression and activity. While genetic information is encoded by the (genome's) DNA sequence, methylation and other types of histone modifications regulate genome organization and gene expression.

The study found hundreds of loci (the places genes occupy on chromosomes) across the genome affected by altered histone methylation in the brains of autistic individuals. However, only a small percentage – less than 10 percent – of the affected genes were affected by DNA mutations. It remains to be determined whether or not genetic changes elsewhere in the genome contributed to the observed epigenetic changes, or whether non-genetic factors were responsible for the disease process in some of the affected individuals.

" neurons from subjects with autism show changes in chromatin (the substance of chromosomes) structures at hundreds of loci genome-wide, revealing considerable overlap between genetic and epigenetic risk maps of developmental brain disorders," the authors conclude.

Explore further: Tiny, spontaneous gene mutations may boost autism risk

More information: Arch Gen Psychiatry. Published online Nov. 7, 2011. doi:10.1001/archgenpsychiatry.2011.151

Related Stories

Tiny, spontaneous gene mutations may boost autism risk

March 15, 2007

Tiny gene mutations, each individually rare, pose more risk for autism than had been previously thought, suggests a study funded in part by the National Institute of Mental Health, a component of the National Institutes of ...

Autism blurs distinctions between brain regions

June 3, 2011

Autism blurs the molecular differences that normally distinguish different brain regions, a new study suggests. Among more than 500 genes that are normally expressed at significantly different levels in the front versus the ...

Recommended for you

Why we fall prey to misinformation

August 23, 2016

Even when we know better, we often rely on inaccurate or misleading information to make future decisions. But why are we so easily influenced by false statements such as "vaccinations cause autism" or "30 million illegal ...

Sleep makes relearning faster and longer-lasting

August 22, 2016

Getting some sleep in between study sessions may make it easier to recall what you studied and relearn what you've forgotten, even 6 months later, according to new findings from Psychological Science, a journal of the Association ...

Have we misunderstood post-traumatic stress disorder?

August 22, 2016

In understanding war-related post-traumatic stress disorder, a person's cultural and professional context is just as important as how they cope with witnessing wartime events, which could change the way mental health experts ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.