Abstract: SA-PO357
Spontaneous Remission of Genetic, Apparently Primary FSGS Presenting with Nephrotic Syndrome Challenges Traditional Notions of Primary and Genetic FSGS
Session Information
- Genetic and Diagnostic Trainee Case Reports
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Report
- 1002 Genetic Diseases of the Kidneys: Non-Cystic
Authors
- Oo, Swe Zin Mar Win Htut, University of Iowa, Iowa City, Iowa, United States
- Patel, Jayesh B., University of Iowa, Iowa City, Iowa, United States
- Freese, Margaret E., University of Iowa Hospitals & Clinics, Iowa City, Iowa, United States
- Thomas, Christie P., University of Iowa College of Medicine, Iowa City, Iowa, United States
Introduction
Focal segmental glomerulosclerosis (FSGS) presenting with nephrotic syndrome (NS) with focal sclerosing lesions and diffuse foot process effacement (FPE) is considered diagnostic of primary FSGS. KDIGO guidelines advise against genetic testing in adult idiopathic FSGS. We report a case of genetic FSGS that presented with NS and biopsy features of primary FSGS which resolved spontaneously.
Case Description
A 26-year-old healthy Caucasian female was referred for new onset NS. She had peripheral edema, a BP of 157/110 a urine protein creatinine ratio (UPC) of 9.04, a serum albumin of 2.3 mg/dl and a serum creatinine of 1.2 (eGFR 62). Other serological tests were negative. A kidney biopsy showed focal, segmental sclerosis in 2 of 47 glomeruli with diffuse FPE on EM consistent with primary FSGS. She declined corticosteroid treatment. She was treated with lisinopril/furosemide. Genetic testing showed a missense variant (p.Asn125Ser) in TRPC6. This missense variant is ultrarare, is predicted pathogenic and was previously reported in two pedigrees with FSGS with demonstrated gain of function in vitro. We continued conservative therapy and 8 months after diagnosis she has had complete remission with her UPC declining to 0.67, serum albumin improving to 4.3 and serum creatinine to 0.9 (eGFR 88).
Discussion
Most authors differentiate primary FSGS from all other causes including genetic and adaptive forms of FSGS. Our case demonstrates that genetic FSGS cannot be differentiated clinically from primary FSGS and can undergo spontaneous remission. Given prognostic and therapeutic implications, we suggest that genetic testing be performed in any young adult with FSGS prior to a therapeutic trial with high dose steroids.