We initiated this study after the identification of a de novo c.1912G>A (p.Gly638Ser) variant in KDM2B (NM_032590.4; Table 1; Supplemental Table 1) through diagnostic trio exome sequencing in the index patient (individual 1), who was diagnosed with speech delay, autism spectrum disorder (ASD), and a congenital heart defect (CHD) (Table 2; Supplemental Table 2). The gene discussed is KDM2B; the disease is Delayed speech and language development.