Autism: the label given to a wide and diverse variety of neurodevelopmental disorders

Autism and autism-like disorders are associated with a fairly large number of gene addresses associated with the clinical diagnosis of "autism":

Int J Dev Neurosci. 2007 Apr;25(2):69-85. Epub 2006 Dec 20. A review of gene linkage, association and expression studies in autism and an assessment of convergent evidence. Yang MS, Gill M.

In this article we review the past and present literature on neuro-pathological, genetic linkage, genetic association, and gene expression studies in this disorder. We sought convergent evidence to support particular genes or chromosomal regions that might be likely to contain risk DNA variants. The convergent evidence from these studies supports the current hypotheses that there are multiple genetic loci predisposing to autism, and that genes involved in neurodevelopment are especially important for future genetic studies. Convergent evidence suggests the chromosome regions 7q21.2-q36.2, 16p12.1-p13.3, 6q14.3-q23.2, 2q24.1-q33.1, 17q11.1-q21.2, 1q21-q44 and 3q21.3-q29, are likely to contain risk genes for autism.

It's more evident all the time that we use the word "autism" to describe a diverse group of neuro-developmental disorders with different prognosis and course. It's very hard to come up with good treatments if we're mixing different disorders -- one persons treatment may be ineffective or harmful to another. We need to divide "autism" into at least a half-dozen better characterized disorders.