Noonan Syndrome With Complex Pulmonary Stenosis at High Altitude: Impact of Delayed Diagnosis.

ABSTRACT:

Background

Noonan syndrome is a genetic disorder affecting 1 in 1,000 to 2,500 live births, with cardiac involvement in up to 80% of cases, predominantly pulmonary valve stenosis. Socioeconomic barriers often delay diagnosis in resource-limited settings.

Case summary

A 22-year-old male presented with severe oxygen desaturation at high altitude, initially attributed to COVID-19. Clinical evaluation revealed characteristic Noonan syndrome features and a grade IV/VI systolic murmur. Cardiac imaging demonstrated severe dysplastic pulmonary stenosis with supravalvular membrane, right-to-left shunting through an atrial septal defect, and an anomalous right coronary artery. The patient underwent pulmonary valve replacement, right ventricular outflow-tract enlargement, atrial septal

SUBMITTER: Torres-Valencia J 

PROVIDER: S-EPMC12478504 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature