Genetic factors increase the risk of developing autism spectrum disorder (ASD), but the specific genetic cause for an individual patient can be elusive.
Genetic testing is crucial to identifying a cause for ASD in many children who do not have an easily recognisable genetic syndrome. Current guidelines exist for 2 types of genetic testing — G-banded karyotype and fragile X DNA testing.
In the study, �Clinical Genetic Testing for Patients with Autism Spectrum Disorders,� published in the April issue of Pediatrics, Yiping Shen, PhD, Autism Consortium, Boston, Massachusetts, and colleagues compared these 2 methods of genetic testing with a third method: chromosomal microarray (CMA).
In a cohort of 933 patients with ASD, karyotype testing found 19 of 852 patients (2.2%) had abnormal genetic results, and fragile X testing was abnormal in 4 of 861 patients (0.4%).
In comparison, CMA identified abnormal results in 59 of 848 patients (7%), yielding the highest detection rate of the 3 tests.