Common Allele Confers Susceptibility to Autism
Gene variant causes reduced MET expression, which may affect brain development
FRIDAY, Oct. 20 (HealthDay News) -- New research suggests that a common mutation in the promoter for the MET receptor tyrosine kinase gene is associated with a more than twofold increase in risk for autism, according to a report published online Oct. 19 in the Proceedings of the National Academy of Sciences Early Edition. Such a genetic link to autism is so far "unprecedented" in the literature, the author of an accompanying editorial points out.
MET is involved in brain development, immune system regulation and gastrointestinal repair, all of which are affected by autism, so Daniel B. Campbell of Vanderbilt University in Nashville, Tenn., and colleagues examined MET gene status in 1,231 cases of autism.
The authors identified a common MET variant allele, called the C allele, in 204 families with autism and confirmed the association in an additional 539 families. Homozygosity for the C allele was found to confer a 2.27-fold higher risk for autism compared with individuals who were homozygous GG for the allele. The mutation reduces the level of MET expression, which may affect signaling pathways controlling brain development.
The report "takes the next step in solving the puzzle of autism spectrum disorder genetics," and provides "exciting genetic and biochemical evidence pointing to a common functional variant in the promoter of the MET gene as the contributing risk factor," writes Matthew State, M.D., Ph.D., of Yale University School of Medicine in New Haven, Conn., in an editorial.