Abstract: SA-PO386
Cystinuria Screening Reveals Uncontrolled Hypertension and Subnephrotic-Range Proteinuria in a 20-Year-Old Patient: A Case Report
Session Information
- Hypertension, CVD, and the Kidneys: Clinical Research
October 26, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Hypertension and CVD
- 1602 Hypertension and CVD: Clinical
Authors
- Mumin, Muhammed, University of Rochester, Rochester, New York, United States
- Zabiullah, Syed Mohammed Faizaan, Unity Hospital, Rochester, New York, United States
- Zahid, Viqarunnisa Faaiza, University of Minnesota Twin Cities, Minneapolis, Minnesota, United States
- Levy, Rebecca V., University of Rochester, Rochester, New York, United States
- Drury, Erika, University of Rochester, Rochester, New York, United States
- Yousuf, Mohammad Azmal, University of Rochester, Rochester, New York, United States
- Jean-Gilles, Jerome Louis, University of Rochester, Rochester, New York, United States
Introduction
Cystinuria is an autosomal recessive disorder caused by defects in the SLC3A1 gene that mediates sodium-independent transport of cysteine and dibasic amino acids in proximal tubule and small intestine. Cystinuria commonly presents as renal stones.
Case Description
A 20 y.o male with history of ADHD on amphetamine-dextroamphetamine presented for cystinuria screening. Family history was notable for a sister with cystinuria. He had no complaints. On examination, he is a young muscular man with BMI of 23.7 kg/m2. His office BP is 134/63 mm Hg. Physical examination is otherwise unremarkable. Urinalysis showed +1 protein. 24 hour urine showed proteinuria of 1842 mg/day, microalbuminuria of 1124.4 mg/day and cystinuria (1096 mg/day). The eGFR (CKiD U25) was 103 ml/min/1.73m2. Serology and immunological workup was normal. Renal biopsy revealed diffuse segmental mesangiolysis and IgM mesangial deposits of unclear significance. EM showed glomerular BM thickening (286-796 nm) with segmental lamina rara interna expansion and mesangiolysis. The overall findings were suggestive of chronic endothelial injury. Ambulatory BP monitoring showed markedly elevated BP readings(mean systolic 152 mm Hg). Preliminary diagnosis was masked hypertension with hypertensive kidney disease, lisinopril was started and stimulant was discontinued. Endocrine evaluation for secondary hypertension was negative. Echo revealed LV hypertrophy. Genetic testing showed biallelic pathogenic mutations in SLC3A1 consistent with known cystinuria.
Discussion
This case highlights a rare combination of cystinuria and hypertensive kidney disease. It is unclear in this patient whether the cystinuria and hypertension are linked. It also emphasizes the importance of screening of close family members for Cystinuria, which in this patient has led to early discovery of his hypertension and prevented severe end-organ damage.