Pulmonary Arterial Hypertension Associated with Connective Tissue Disease, also known as pah associated with connective tissue disease, is related to pulmonary hypertension, primary, 1 and connective tissue disease. An important gene associated with Pulmonary Arterial Hypertension Associated with Connective Tissue Disease is HLA-B (Major Histocompatibility Complex, Class I, B). The drugs Bosentan and Endothelin Receptor Antagonists have been mentioned in the context of this disorder. Affiliated tissues include heart and lung.