Table 1 Clinical classification of WHO group 1 pulmonary hypertension

1. Pulmonary arterial hypertension (PAH)

 1.1 Idiopathic PAH

 1.2 Heritable PAH

  1.2.1 BMPR2

  1.2.2 ALK-1, ENG, SMAD9, CAV1, KCNK3

  1.2.3 Unknown

 1.3 Drug- and toxin-induced

 1.4 Associated with:

  1.4.1 Connective tissue disease

  1.4.2 HIV infection

  1.4.3 Portal hypertension

  1.4.4 Congenital heart disease

  1.4.5 Schistosomiasis

1′ Pulmonary veno-occlusive disease and/or pulmonary capillary hemangiomatosis

1″ Persistent pulmonary hypertension of the newborn (PPHN)