Autism researchers make huge step in discovering genetic mutations that may lead to the disorder

Genome research has been a boon for unravelling the mysteries surrounding autism, allowing scientists to identify around 100 altered genes associated with the neurodevelopmental disorder.

But genome research has also compounded the puzzle of autism. Those who display the symptoms of autism spectrum disorder (ASD) may carry the same number of genetic mutations as their unaffected siblings. One person with ASD will carry mutations totally different from the next, and half of those diagnosed will have none of the known mutations at all.

There are no common patterns, says Stephen Scherer, director of the Hospital for Sick Childrens Centre for Applied Genomics.

By examining a different part of the genome than previously studied, a team of scientists led by Scherer has created a formula for determining which mutations are likely to lead to ASD and which are not. In the process, they also flagged more than 1,600 genes not previously linked to autism that may hold new clues for discovering what causes the disorder that now affects 1 in 68 children.

The new research, published in the journal Nature Genetics, suggests that autism begins to develop in the womb. It will help clinicians diagnose ASD earlier hugely important, since autism is easier to treat the earlier it is caught.

Kathryn Roeder, a statistical geneticist at Carnegie Mellon University in Pittsburgh who was not involved in the study, called it a tremendous stride forward, saying she planned to distribute it as soon as she could.

The new formula, Roeder said, will be able to erase a lot of noise.

The formula came about after researchers in Scherers lab decided to examine exons, small segments of DNA that are protein-coding. An average gene has 10 exons, but may have fewer or many more.

The team discovered that when they compared mutations in the exons of those who have ASD and those who do not, rather than comparing the whole genome, they came up with a statistically significant way of predicting ASD symptom risk.

You have to look at the small segment level, the exon level. Thats really the key here, says Scherer.

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Autism researchers make huge step in discovering genetic mutations that may lead to the disorder