What is the most likely etiology of pulmonary arterial hypertension (PAH) in a patient with a strong family history of PAH?

The most likely etiology of pulmonary arterial hypertension (PAH) in a patient with a strong family history is related to heritable factors. This connection arises from the understanding that certain genetic mutations can predispose individuals to PAH. Specifically, heritable pulmonary arterial hypertension is often caused by mutations in the bone morphogenetic protein receptor type 2 (BMPR2) gene, among others, which can lead to vascular remodeling and increased pulmonary artery pressure.

In cases with a strong family history, it suggests an inherited component rather than an idiopathic nature of the disease, as idiopathic PAH typically occurs sporadically without a familial link. Additionally, while heart failure can lead to increased pulmonary pressures, it is not an inherent cause of PAH and is more of an overall consequence of other conditions. Similarly, drug-induced factors may contribute to PAH in certain scenarios but typically do not explain familial patterns of the disease.

The emphasis on heritable factors underscores the importance of genetic predisposition in the development of PAH, particularly evident in families where multiple members are affected. Recognizing this aspect can aid in better management strategies and genetic counseling for families at risk.