Currently, most diagnostic labs offering mutational analysis for HHT focus on analyzing only ACVRL1, ENG and SMAD4. To determine whether RASA1 and GDF2 should be included in HHT panel testing, we utilized next-generation sequencing (NGS) to test for RASA1 and GDF2 mutations in 93 patient samples clinically suspected to have HHT that had previously tested negative for mutations in ENG, ACVRL1 and SMAD4. The gene discussed is SMAD4; the disease is hereditary hemorrhagic telangiectasia.