Risk and Resilience in Pulmonary Arterial Hypertension and Genetically Susceptible Individuals

Inclusion Criteria: * Children and Adults, aged 15 - 80 * Diagnosed with idiopathic or heritable, pulmonary arterial hypertension (PAH), defined according to standard criteria * Unaffected Mutation Carriers: Healthy participants with a known BMPR2 gene mutation and normal pulmonary pressure and RV function on echo * Healthy Controls: Healthy individuals without cardiopulmonary disease. * WHO functional class I-III * Stable PAH-specific medication regimen for three months prior to enrollment. Subjects with only a single diuretic adjustment in the prior three months will be included. Adjustments in IV prostacyclin for side effect management are allowed. Exclusion Criteria: * Prohibited from normal activity due to wheelchair bound status, bed bound status, reliance on a cane/walker, activity-limiting angina, activity-limiting osteoarthritis, or other condition that limits activity. * Pregnancy * Diagnosis of PAH etiology other than idiopathic, heritable * Functional class IV heart failure * Requirement of \> 2 diuretic adjustment in the prior three months.