Abstract: FR-PO444
Glycogen Storage Disease Type 1a Leading to Recurrent Nephrolithiasis
Session Information
- Pediatric Nephrology - I
November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Genetic Diseases of the Kidneys
- 1102 Genetic Diseases of the Kidneys: Non-Cystic
Authors
- Gandhi, Nisarg, Houston Methodist, Houston, Texas, United States
- Bazerbashi, Noor, Houston Methodist, Houston, Texas, United States
- Ibrahim, Hassan N., Memorial Hermann Health System, Houston, Texas, United States
Introduction
Nephrolithiasis is a common presenting problem, but recurrence especially at a young age should prompt further laboratory and genetic testing to determine the cause. Herein, we present a case of autosomal recessive glycogen storage disease type 1a with recurrent symptomatic kidney stones.
Case Description
A 19-year-old Caucasian man presents to clinic for evaluation of recurrent kidney stones at the ages of 10, 11, and 17. A previous CT scan from 2 years prior revealed multiple bilateral kidney stones and a previous stone analysis revealed its composition to be 50% calcium oxalate monohydrate and 50% calcium oxalate dihydrate. His laboratory testing revealed a parathyroid hormone level of 21 pg/mL, calcium of 10.0 mg/dL, creatinine of 0.92 mg/dL, and uric acid level of 5.1 mg/dL, all within normal limits. A Litholink 24-hour urine collection was conducted to evaluate for cause of kidney stones (Table 1). Given the hypocitraturic and hypercalciuric state at a young age with family history of kidney stones, a Natera genetic test was ordered. The results revealed autosomal recessive gene for glycogen storage disease type 1a. Subsequently, he was started on chlorthalidone and potassium citrate to lower urinary calcium and increase urinary citrate, respectively, to decrease his risk of developing additional kidney stones. At his most recent visit, the 24-hour urinary calcium had improved significantly, but the urinary citrate remained low (Table 1).
Discussion
Glycogen storage disease is a rare autosomal recessive disorder of fat and glycogen processing in the liver and kidneys, leading to a wide range of metabolic disturbances including hyperuricemia, hyperlipidemia, and fasting hypoglycemia. Kidney stones have been previously reported in approximately 6% of cases with hypercalciuria and hypocitraturia. Typically, uric acid levels are high in the serum and urine, but not necessary for diagnosis. Treatment involves decreasing urinary calcium, increasing urinary citrate, and decreasing urinary uric acid. Long-term symptom management is necessary to prevent progression to CKD. This case illustrates the utility of genetic testing in patients with recurrent nephrolithiasis, especially at a young age.
Table 1: Litholink Results
| 24-Hour Urine Collection (Reference Range) | Volume (0.5-4.0 L) | Calcium (male < 250 mg) | Citrate (male >450 mg) | Uric Acid (male < 0.800 g) |
| Initial | 4.17 | 326 | 222 | 0.535 |
| 6 Months Later | 2.03 | 134 | 182 | 0.421 |