A paper titled “Molecular Diagnostic Yield of Chromosomal Microarray Analysis and Whole-Exome Sequencing in Children With Autism Spectrum Disorder” was published by JAMA today.

In the study, the authors compared the diagnostic yield of chromosomal microarray analysis (CMAs) versus exome sequencing for autism spectrum disorders (ASDs). They assayed 258 consecutively ascertained unrelated children with ASD who underwent detailed assessments to define morphology scores based on the presence of major congenital abnormalities and minor physical anomalies. Interestingly, they found that the molecular diagnostic yields of CMA (9.3%) and WES (8.4%) were comparable, and the combined molecular diagnostic yield (15.8%) was higher in children with more complex morphological phenotypes.

By classifying the patients into phenotype groups, they found that the combined molecular diagnostic yield was 6.3% in the essential group, 28.6% in the equivocal group, and 37.5% in the complex group. Therefore, for children with more complex morphological phenotypes, it may require the combined use of CMA and exome sequencing to improve the diagnostic rates.

The sample size in this study is relatively modest; however, it provides a reference on the diagnostic rate and suggest the added value of exome sequencing as a second-tier diagnostic tool, especially for ASD patients with complex morphological phenotypes.

The article can be accessed at here.