Abstract: PUB181
Proteinuria Behind the Scenes: An Occult Diagnosis of Alport Syndrome in a Woman via Genetic Testing
Session Information
Category: Trainee Case Report
- 1002 Genetic Diseases of the Kidneys: Non-Cystic
Authors
- Farmakis, Christopher, Methodist Dallas Medical Center, Dallas, Texas, United States
- Qureshi, Muhammad Raza, Dallas Nephrology Associates, Dallas, Texas, United States
- Collazo-Maldonado, Roberto L., Dallas Nephrology Associates, Dallas, Texas, United States
Introduction
Alport Syndrome is a rare disease amongst children and adults. The diagnosis is a clinical challenge for adult nephrologists. We illustrate a case demonstrating the use of genetic testing to confirm the diagnosis.
Case Description
The patient is a 23-year-old woman who presented with nephrotic syndrome. She was found to have proteinuria of 3.2 grams, glomerular hematuria, and a creatinine of 1.6 mg/dL. The patient endorsed a family history of End Stage Kidney Disease (ESKD) in her sister. A complete serologic work-up and renal ultrasonography were negative. Kidney biopsy was performed, which showed Focal Segmental Glomerular Sclerosis (FSGS) with diffuse foot process effacement. The patient was started on steroids and lisinopril. After 6 months, the patient did not improve. Genetic testing for Alport Syndrome was positive for the COL4A4 mutation, confirming a diagnosis of autosomal Alport Syndrome despite a lack of classic symptoms.
Discussion
Alport Syndrome affects one in every 5000 to 10000 adult Americans and causes 0.2% of all ESKD cases in the United States. The pathophysiology involves a lamellated glomerular basement membrane with abnormal collagen IV composition. The majority (85%) of cases are inherited in an X-linked pattern via the COL4A5 mutation. Autosomal recessive, and less commonly autosomal dominant, patterns are seen with mutations in the COL4A3 and COL4A4 genes. It is characterized by progressive renal failure, hematuria, hearing loss, and ocular abnormalities. Kidney biopsy in such patients has been reported to show FSGS, as in our patient. In the appropriate clinical context, the gold standard for diagnosis remains genetic testing. Treatment involves supportive care and RAAS blockade to slow the progression to ESKD.
In 2021, the use of novel genetic testing can be more accessibly done in the clinic setting. These tests can uncover various renal pathologies which may otherwise have gone undiagnosed, as is what occurred in our case. Therefore, we believe the more routine use of genetic testing by nephrologists allows for better overall patient care.