Expanding the phenotypic spectrum of <i>MECOM</i> -associated syndrome: rare variants are associated with syndromic pulmonary arterial hypertension

Rare <i>MECOM</i> variants are associated with early-onset syndromic PAH. PAH monitoring should be considered for all individuals with rare <i>MECOM</i> variants. We speculate that the pathogenetic mechanism for PAH and cardiac defects may be impaired <i>VEGFR2</i>/<i>KDR</i> signalling.