March 22, 2007 -- Japanese researchers report that glitches in a gene they studied -- called the CADPS2 gene -- may be associated with autism.
Several other genes have been linked to autism. However, the disorder's exact cause and its full genetic profile are not yet established.
Last week, an American gene expert told WebMD that 100 or more genes may affect autism risk.
The Japanese scientists in this study included Teiichi Furuichi, PhD, of the Laboratory for Molecular Neurogenesis at the RIKEN Brain Science Institute in Wako, Japan.
They studied the CADPS2 gene in mice as well as in people.
In lab tests, the researchers deleted part of the CADPS2 gene in mice. For comparison, they left the gene intact in other mice.
The mice with the disrupted CADPS2 gene became less social and less interested in exploring a new environment than mice with an intact CADPS2 gene.
Those with the disrupted CADPS2 gene also became hyperactive and started having disruptions in their sleep patterns. However, their vision, hearing, smell, and motor skills were similar to mice with an intact gene.
The behavioral changes in the mice with the disrupted CADPS2 gene are similar to several autism symptoms, the researchers point out.
Furuichi and colleagues also screened the genes of 252 autistic patients. They found seven unusual arrangements of DNA within the CADPS2 gene in these patients.
The DNA patterns seen haven't been reported in healthy people without autism, note Furuichi and colleagues.
However, Furuichi's team stresses that their human DNA studies don't prove that those particular CADPS2 variations cause autism.