Autism: GenomeWide Hunt Reveals New Genetic Links.

(From AScribe)

BALTIMORE -- About 90 percent of autism spectrum disorders have suspected genetic causes but few genes have been identified so far. Now, leading an international team, Johns Hopkins researchers have identified several genetic links to autism, chief among them a variant of semaphorin 5A, whose protein product controls nerve connections in the brain.

Semaphorin 5A had already been known to help guide growing neurons to the right connecting points in the brain during fetal development. To verify that semaphorin 5A plays a role in autism, the researchers looked at brain tissue samples from the Autism Tissue Program and the Harvard Brain Bank, and found the amount of the semaphorin 5A protein to be significantly reduced in …