Saudi guidelines on the diagnosis and treatment of pulmonary hypertension: genetics of pulmonary hypertension

Pulmonary hypertension [PH] is a phenotype characterized by functional and structural changes in the pulmonary vasculature, leading to increased vascular resistance. [1], [2] The World Health Organization has classified PH into five different types: arterial, venous, hypoxic, thromboembolic or miscellaneous; details are available in the main guidelines. Group I of this classification, designated as pulmonary arterial hypertension [PAH], will remain the main focus here. The pathophysiology involves signaling, endothelial dysfunction, activation of fibroblasts and smooth muscle cells, interaction between cells within the vascular wall, and the circulating cells; as a consequence plexiform lesions are formed, which is common to both idiopathic and heritable PAH but are also seen in other forms of PAH. [2], [3], [4] As the pathology of PAH in the lung is well known, this article focuses on the genetic aspects associated with the disease and is a gist of several available articles in literature