Can clinical characteristics be criteria to perform chromosomal microarray analysis in children and adolescents with autism spectrum disorders?

Background: Chromosomal microarray analysis (CMA) has become increasingly important in the assessment of patients with autism spectrum disorders (ASD), but is sometimes restricted to patients with specific additional characteristics or comorbidities. We aim to evaluate whether certain clinical characteristics could be criteria to perform CMA and also to investigate the diagnostic value of CMA compared to other genetic analyses in our patient population.

Methods: The files of 311 children diagnosed with ASD were retrospectively analyzed. The retrieved clinical characteristics included: intellectual disability, major congenital anomalies, epilepsy, prematurity, familial history of ASD, electroencephalography, and brain MRI findings. Results of the genetic analyses, including CMA, were collected and statistical analysis was performed.

Results: CMA was performed in 79 patients and was found to be normal in 55 (group 1) and abnormal in 23 children (group 2). We found no statistically significant difference between groups in the presence of the clinical characteristics. The diagnostic yield of CMA (8.9%) was higher than in conventional karyotyping (1.6%) and other genetic analyses (3.8%).

Conclusions: In our study, there was no significant difference in the presence of clinical characteristics in patients diagnosed with ASD who had abnormal CMA results compared to patients with normal CMA results. Therefore, the presence of these characteristics should not be used as criteria to perform CMA. Secondly, the diagnostic yield of CMA is higher than that of other genetic analyses. Our study supports the general recommendation that CMA should be offered as a first-tier test in the assessment of patients with ASD.