CAV1 and pulmonary arterial hypertension: The CAV1 variant was observed in unaffected members of this family and this was interpreted as, potentially, being due to incomplete penetrance in a similar vein to mutations of BMPR2. Analysis of a replication cohort by Sanger sequencing led to the identification of a second premature truncation (c.473delC) in a single IPAH case lending plausibility to the likelihood of the gene representing a rare inherited risk factor in familial PAH [101].