Publication date: Sep 17, 2025
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. 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 defect closure, and unplanned aortic valve replacement for unexpected moderate insufficiency. Despite postoperative complications, 4-year follow-up showed excellent outcomes. This case illustrates how high-altitude physiology exacerbates right-to-left shunting in congenital heart disease and highlights how socioeconomic barriers delay critical interventions, emphasizing the need for improved healthcare accessibility in marginalized populations.
| Concepts | Keywords |
|---|---|
| Coronary | computed tomography |
| Genetic | congenital heart defect |
| Live | echocardiography |
| Socioeconomic | imaging |
Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | Noonan Syndrome |
| disease | MESH | Pulmonary Stenosis |
| disease | MESH | genetic disorder |
| disease | MESH | live births |
| drug | DRUGBANK | Oxygen |
| disease | MESH | COVID-19 |
| disease | MESH | systolic murmur |
| disease | MESH | atrial septal defect |
| disease | MESH | postoperative complications |
| disease | MESH | congenital heart disease |