A 17-gene PAH next-generation sequencing panel (ACVRL1, AQP1, ATP13A3, BMPR1B, BMPR2, CAV1, EIF2AK4, ENG, EPHB4, GDF2, KCNA5, KCNK3, RASA1, SMAD4, SMAD9, SOX17, and TBX4), which included all genes associated with HHT as well as its associated phenotypically overlapping syndromes, was found to be negative except for a homozygous variant in ACVRL1 (NM 000020.2; c.576C>G; p.Phe192Leu). This evidence concerns the gene SMAD4 and hereditary hemorrhagic telangiectasia.