Better genetic test for autism

Washington, March 15 : A new study has found that a genetic test that samples the entire genome, known as chromosomal microarray analysis (CMA), has about three times the detection rate for genetic changes related to autism than standard tests.

Researchers from Children''s Hospital Boston and the Boston-based Autism Consortium, who conducted the study, urge that CMA become part of the first-line genetic work-up for autism spectrum disorders (ASDs).

The study, led by Consortium members Bai-Lin Wu, David Miller, Kira Dies, and Yiping Shen, examined 933 families (children and parents) who received clinical genetic testing for a diagnosis of Autism Spectrum Disorder (ASD) between January 2006 and December 2008.

The researchers compared the findings from three clinical genetic tests: G-banded karyotype and fragile X testing, the current standard battery of genetic testing, and chromosomal microarray analysis, for which testing guidelines have not yet been established.

Chromosomal microarray analysis is similar to a karyotype, but can find much smaller chromosomal deletions and duplications.

The results showed that chromosomal microarray analysis identified more genetic abnormalities associated with autism than the standard testing methods combined.

"This is the largest study of clinical genetic testing for patients with autism spectrum disorders, and the results clearly show that chromosomal microarray analysis detects genetic abnormalities leading to ASD more often than a standard karyotype and fragile X testing," said David Miller, assistant director of the DNA Diagnostic Laboratory at Children''s.

The study has been published in the April issue of Pediatrics.