Recently, exome sequencing was used to identify missense mutations in the bone morphogenetic 9 (BMP9) gene (GDF2, chromosome 10q11) in two unrelated individuals suspected to have HHT who previously tested negative for ENG, ACVRL1, and SMAD4. A third case was identified by Sanger sequencing of GDF2 in additional such individuals (Wooderchak-Donahue et al., 2013). This evidence concerns the gene SMAD4 and hereditary hemorrhagic telangiectasia.