Is pulmonary arterial hypertension inherited ?
Pulmonary arterial hypertension is usually sporadic, which means it occurs in individuals with no known family history of the disorder. These non-familial cases are described as idiopathic pulmonary arterial hypertension. About 20 percent of these cases are caused by mutations in one of the genes known to be associated with the disease, but most of the time a causative gene mutation has not been identified.  Inherited cases of this disorder are known as familial pulmonary arterial hypertension. When the condition is inherited, it most often has an autosomal dominant pattern of inheritance, which means one copy of an altered gene in each cell is sufficient to cause the disorder. However, many people with an altered gene never develop pulmonary arterial hypertension; this phenomenon is called reduced penetrance.