Quiz Ref IDChildren with neurodevelopmental disorders, including developmental delay, intellectual disability, autism spectrum disorder (ASD), or congenital anomalies may have genetic abnormalities that traditionally were detected using analysis. Karyotyping identifies clinically relevant genetic abnormalities in approximately 5% of children with these disorders.¹ However, karyotyping has now been replaced by chromosomal microarray analysis (CMA), which detects unbalanced chromosomal rearrangements like G-banded karotyping but also detects smaller chromosome abnormalities, increasing the diagnostic yield to approximately 20% of patients.^1,2 Because of its greater sensitivity, CMA tests should now be considered by any clinician evaluating a child with otherwise unexplained developmental delay, intellectual disability, ASD, or congenital anomalies () (Figure).