Which of the following genes is associated with familial pulmonary aerial hypeension?

The first mutation to be discovered in familial pulmonary aerial hypeension was in the gene encoding bone morphogenetic protein receptor type 2 (BMPR2). Inactivating germline mutations in the BMPR2 gene are found in 75% of the familial cases of pulmonary hypeension and 25% of sporadic cases. BMPR2 is a cell surface protein belonging to the TGF-b receptor superfamily, which binds a variety of cytokines, including TGF-b, bone morphogenetic protein (BMP), activin, and inhibin. Haploinsufficiency for BMPR2 leads to dysfunction and proliferation of endothelial cells and vascular smooth muscle cells.