Pulmonary arterial hypertension (PAH), or high blood pressure in the lungs, is a rare condition that can shorten life. Although the cause of this disease is usually unknown, in about 70% of heritable and 15-20% of idiopathic cases there is a change in a gene (a mutation) that controls how blood vessels grow and function. The gene is called bone morphogenetic protein type receptor 2 (BMPR2). Although mutations in BMPR2 are a risk factor for PAH, not everyone with a mutation gets the disease. Additional genetic and environmental factors are likely to contribute. The investigators suspect that mutations in other genes are responsible for some cases of PAH. In this study the investigators aim to recruit all patients with PAH and some of their relatives and follow them up for several years. The investigators hope to discover new mutations for this disease and to determine what factors lead to poor outcome, and to understand what triggers disease in patients with mutations.

Who can participate? Adults with PAH, their relatives and controls (one off blood sample)

What does the study involve?

PAH patients will be seen at their local centre by their service team but they will have additional bloods taken. Relatives of PAH patients will be seen every year at their nearest PAH centre. Tests will include:

• Epidemiology Questionnaire to assess factors affecting health
• An echocardiogram (ECHO) to assess the size, shape, pumping action and the extent of any damage to the heart.
• Lung function tests which include blowing measurements to assess gas volumes within the lungs as well as assessment of how the lungs exchange gases.
• Optional right heart catheterisation (RHC) to determine how much blood your heart is pumping while you are resting and on exercise. Optional Cardiac Magnetic Resonance tests. To measure heart function. ( to be done only once)
• 6 minute walk test. To measure exercise capacity
• Cardiopulmonary exercise test. A bicycle exercise test, which will indicate how much blood your heart pumps while resting and with different levels of exercise.
• Electrocardiogram (ECG), a test that measures the electrical activity of the heart
• Blood tests

Controls:Blood sample and medical data collected once

Inclusion Criteria:

Inclusion Criteria-Patient

• Participant is willing and able to give informed consent for participation in the study.
• Male or Female, any age
• Diagnosed with idiopathic, anorexigen-induced,heritable PAH, PVOD/PCH. Inclusion Criteria-Relative
• Participant is willing and able to give informed consent for participation in the study.
• Male or Female, any age
• Has a family member diagnosed with idiopathic, anorexigen-induced, PVOD/PCH or heritable PAH

Exclusion Criteria-Patient

The participant may not enter the study if ANY of the following apply:

• Patient is unable to give informed consent.
• Not suffering from idiopathic, anorexigen-induced, PVOD/PCH or heritable PAH

Exclusion Criteria-Relative

The participant may not enter the study if ANY of the following apply:

• Patient is unable to give informed consent.

Inclusion criteria-Controls

• Participant is willing and able to give informed consent for participation in the study.
• Self-reported to be healthy
• Age range up to 75 years

Patients diagnosed with idiopathic, anorexigen-induced, heritable PAH or PVOD. Relative who has a family member diagnosed with idiopathic, anorexigen-induced, heritable PAH or PVOD/PCH

Consent for sharing of non identifiable study data for regulatory authorities, third parties including commercial companies outside the UK and NHS trusts where it is relevant to taking part in this research.