Clinical Utility of Proband Only Clinical Exome Sequencing in Neurodevelopmental Disorders

Chromosomal microarray is recommended as the first line of investigation in neurodevelopmental disorders (NDDs). However, advances in next-generation sequencing have unraveled more than 900 genes associated with NDDs, thus improving the genetic diagnosis. Therefore, this study was conducted to explore the utility of clinical exome sequencing (CES) in NDDs from a tertiary care centre in India. A retrospective observational analysis of 78 children with NDDs for whom CES was performed between 2017 and 2021 was conducted. The American College of Medical Genetics and Genomics (ACMG) criteria were used to classify the variants. The mean age was 5.8 ± 3.6 y, and 42 (53%) were male. Pathogenic, likely pathogenic, and variants of uncertain significance (VUS) were observed in 22 (28.2%), 10 (12.8%), and 26 (33.3%) patients, respectively, which included five copy number variants. The diagnostic yield for pathogenic and likely pathogenic variants in NDDs by CES was 41%, which was reasonably high.