Mutations associated with Autism

Although autism is highly heritable, sorting out the genes associated with this complex disease has been difficult. Weiss et al. searched for structural mutations (duplications or deletions below the level of microscopic detection) in the genomic DNA of 751 families who are part of the Autism Genetic Resource Exchange. They found a significant association of autism with a nearly 600-kb region that was deleted or duplicated at a locus on chromosome 16. This structural mutation was also observed in patients from Children's Hospital in Boston and in a group from Iceland. It occurred at a frequency of approximately 1% in patients as compared with less than 0.1% of the general population. It might result from unequal crossing over at this region of chromosome 16, which is a known hotspot for deletion and duplication and is bordered by two duplicated regions. Autism may represent the summation of a series of rare events, whose detection will require screening tens of thousands of patient samples.

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Association between Microdeletion and Microduplication at 16p11.2 and Autism. Weiss et al. N. Engl. J. Med. 358, 667 (2008).