Researchers have discovered a distinction between heritable and sporadic forms of Autism. "We found that many children with autism have spontaneous mutations in their DNA," states Jonathan Sebat, one of the leaders of the research at Cold Spring Harbor Laboratory (CSHL). “This occurs more often in the sporadic cases than in either familial cases or in healthy children.
The study was published in the March 16, 2007 edition of Science. It reports that at least 10% of children with autism carry an alteration in their DNA that is not found in either parent. This was seen to be a much higher rate than is observed in healthy children. The researchers observed that spontaneous copy number mutations occur primarily in sporadic cases. The researchers also say that these new mutations were found less frequently in families that have more than one child with autism.
“Our findings suggest that sporadic autism is genetically distinct from the type that runs in families, and that we must use different approaches for studying them," notes Sebat.