14 DAY TRIAL // According to new scientific data, it would appear that the genetic technique known as chromosomal microarray analysis (CMA) is the most suitable method for detecting and identifying conditions pertaining to the autism spectrum disorders (ASD). The conclusion belongs to a comparative study of genetic methods for detecting the diseases, which was conducted by the innovative research, clinical and family collaboration Autism Consortium. Details of the work will appear in the April issue of the highly-respected scientific publication Pediatrics.
Of all clinically-available genetic tests for patients with autism spectrum disorders, CMA has by far the highest detection rate, the experts discovered. As such, the group proposes that the method be introduced as a standard part of initial diagnostic evaluations performed on ASD patients, except for cases in which another type of genetic diagnostic has already been made. The new investigation was conducted by researchers Bai-Lin Wu, David Miller, Kira Dies, and Yiping Shen, all at the Consortium, together with colleagues from the Children's Hospital Boston.
The specialists looked at more than 933 families, including children and parents, all of which had received genetic testing for ASD between 2006 and 2008. Investigations on these families had been conducted using CMA, G-banded karyotype, or fragile X testing. The last two options are part of the existing battery of tests that is applied to autistic children since their infancy, the team says. The thing about CMA, the study showed, is that it still lacks very specific guidelines, which prevents large numbers of experts from using it regularly. Its main advantage over the other two techniques is that it can find much smaller chromosomal deletions and duplications.
“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. Chromosomal microarray was much better than a karyotype, but most clinical guidelines still recommend a karyotype and consider the microarray a second tier test,” explains the Assistant Director of the Children's Hospital Boston DNA Diagnostic Laboratory, David Miller, MD, PhD.
“This study demonstrates the importance of genetic testing for families and clinicians. As we collect more data we will be able to determine the genetic causes of autism. More immediately though, these test results allow clinicians to confirm a genetic component for some families with children on the autism spectrum and even more importantly, gives families an end to the odyssey of trying to find a diagnosis for their child,” concludes the Chief of the Tufts Medical Center Floating Hospital for Children Division of Genetics and Metabolism, Laurie Demmer, MD.