Epidemiological characteristics and treatment patterns of Alport syndrome in Korea

Alport syndrome is the second most common inherited kidney disease, yet many patients remain undiagnosed until advanced kidney failure or receive inappropriate immunosuppressive therapy. Genetic testing indicates it is more common than recognized, but most epidemiological studies have been regional, lacking nationwide assessments.

We analyzed Korean National Health Insurance data, covering the entire population. Patients were identified using the rare disease registration code (V267), requiring laboratory and genetic or histopathological confirmation. We estimated prevalence and incidence, examined therapeutic history before diagnosis, and assessed treatment patterns, particularly renin-angiotensin system (RAS) inhibition.

In 2023, 788 prevalent cases (15.5 per million) were identified; fewer than 10% of the estimated 8,800 COL4A5 male carriers are registered. From 2014 to 2023, 529 incident cases were recorded with a steadily rising incidence. At diagnosis, 30% had been labeled with other glomerulonephritis, with 15% receiving immunosuppressants and 58% RAS inhibitors. After diagnosis, RAS inhibitor use increased by 25%, but immunosuppressive therapy persisted.

This nationwide analysis of registered Alport syndrome cases suggests potential underdiagnosis in Korea, with delays in appropriate recognition and treatment. Many patients receive unnecessary immunosuppression due to misdiagnosis, underscoring the need for improved diagnostic awareness and broader genetic testing.