EPHB4 and atrial septal defect: Other human genetics studies have shown that mutations in the gene encoding the tyrosine kinase receptor EPHB4 (EPHB4, MIM 618196) cause capillary malformation–arteriovenous malformation syndrome (CM-AVM2, including hereditary hemorrhagic telangiectasia and vein of Galen malformations, cutaneous malformations and arteriovenous malformations) and a primary lymphatic anomaly, which includes clinical features such as central conduction lymphatic anomaly, nonimmune fetal hydrops, and atrial septal defects (21–28).