What is being hailed as the largest genome scan ever has come up with two genetic abnormalities in families with at least two member diagnosed with autism. The gene neurexin 1 located on chromosome 2, which is know to be associated with the neurotransmitter glutamate, is one suspect as is several locations on chromosome 11. As many as 30 other genes are also suspects in the disorder and are under investigation. Research in genetics is an important part of the puzzle and these are interesting findings. But I am still puzzled. When you read genetic studies somewhere in the write up autism is referred to as a highly inheritable disorder. However, the concordance rate for identical twins is only 60% and drops to 4-8% for fraternal twins and non-siblings. Without doubt something else is involved in the etiology of autism.
(See Nikhil Swaminathan. http://tinyurl.com/ynr6ey)
