Background Noonan syndrome is a RASopathy inherited in an autosomal dominant manner, mainly caused by gain-of-function variants activating the RAS/mitogen-activated protein kinase signalling pathway. Pulmonary hypertension (PH) may occur in Noonan syndrome, but its mechanisms, clinical characteristics and outcomes remain poorly defined.
Methods We analysed data from the French PH Network to characterise the phenotype of Noonan syndrome patients who develop PH, and conducted a systematic analysis of the literature. Results Seven patients were identified from the French PH Network (male/female ratio 1.3:1), with a median (range) age at PH diagnosis of 9 (5 - 21) years.
Genetic analysis revealed five pathogenic variants in PTPN11 and one in SHOC2 . Associated features included facial dysmorphism, growth retardation, atrial septal defect and pulmonary valve stenosis.
Haemodynamics showed severe pre-capillary PH without acute vasodilator response: mean pulmonary arterial pressure 55 (40 - 78) mmHg, cardiac output 3.95 (3.12 - 4.95) L·min - 1 and pulmonary vascular resistance 13 (10 - 15.3) WU.
European Respiratory Journal published a clinical update in Critical Care on 04 Jun 2026.
The item focuses on Pulmonary hypertension in patients with Noonan syndrome.
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