CDK13 and congenital heart defects, dysmorphic facial features, and intellectual developmental disorder: Congenital heart defects, facial dysmorphism, and intellectual developmental disorder (CHDFIDD) is a newly described syndrome caused by these de novo variants in CDK13.494 Among the affected individuals, 81% displayed some form of cardiac anomaly, with 44% having additional structural cardiac issues, ranging from left pulmonary artery defects to bicuspid aortic valves.494 In a large cohort of 610 patients with congenital cardiac diseases, seven patients with de novo missense mutations in the CDK13 gene were identified, suggesting an involvement of CDK13 in these conditions.495