Kidney Week

Abstract: TH-PO519

Deafness and Bilateral Staghorn Kidney Stones in a Young Patient

Session Information

• Genetic Kidney Diseases: Genotypes and Phenotypes in Cases
  October 24, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Genetic Diseases of the Kidneys

• 1202 Genetic Diseases of the Kidneys: Non-Cystic

Authors

• Nguyen, Hoang Anh, UCLA Medical Center Olive View, Sylmar, California, United States

Hoang Anh Nguyen, DO

• Gopal, Sapna, UCLA Medical Center Olive View, Sylmar, California, United States

Sapna Gopal, MD

• Chandra, Anirudh Vijay, UCLA Medical Center Olive View, Sylmar, California, United States

Anirudh Vijay Chandra, DO

• Kamarzarian, Anita, UCLA Medical Center Olive View, Sylmar, California, United States

Anita Kamarzarian, MD, FASN

• Jafari, Golriz, UCLA Medical Center Olive View, Sylmar, California, United States

Golriz Jafari, MD

• Pham, Phuong-Thu T., Ronald Reagan UCLA Medical Center, Los Angeles, California, United States

Phuong-Thu T. Pham, MD, FASN

• Pham, Phuong-Chi T., UCLA Medical Center Olive View, Sylmar, California, United States

Phuong-Chi T. Pham, MD, FASN

Introduction

Massive stone formation in a young patient requires a thorough evaluation for the underlying cause. With the advent of genetic testing, rare condititions may be diagnosed.

Case Description

A 36-year-old female is referred for bilateral staghorn calculi and recurrent pyelonephritis. Urological history: lithotripsy and percutaneous nephrolithotomy of left kidney, and cystoscopy with stent placement. Medication: none. Review of systems: deafness since childhood. Family history: noncontributory.
Vital signs: blood pressure 126/95 mm Hg, pulse 74, weight 71 Kg, Height 160 cm. Physical examination: within normal limits.
Laboratory studies: Serum sodium 134, potassium 3, chloride 111, total CO2 12 mmol/L; blood urea nitrogen 27, creatinine 3.5, glucose 108, calcium 8.6, phosphorus 3.2, magnesium 2.8 mg/dL; total protein 7.9, albumin 3.9 g/dL; parathyroid hormone 82 pg/mL, vitamin D 25 38 ng/mL. Urinalysis: urine pH 7.0 (persistently >6.5).
Given normal anion gap metabolic acidosis, high urine pH, and hypokalemia, distal renal tubular acidosis (dRTA) type 1 is considered. Serologies for autoimmune disease including ANA, anti-SSA and anti-SSB are negative. Genetic testing reveals homozygous nonsense mutation of ATP6V1B1 gene, encoding H-ATPase, autosomal recessive inheritance.

Discussion

The inherited nonsense mutation of ATP6V1B1 gene is associated with short stature, dRTA, nephrocalcinosis, medullary cysts, hypokalemia, hypokalemic periodic paralysis, and deafness. In the heterozygous state, patients may present with incomplete dRTA, hypercalcemia, and kidney stones. Management includes routine stone management (fluids, potassium supplement as needed). We suspect that the addition of fludrocortisone (in an attempt to acidify the urine) + thiazide diuretic (to both enhenace fludrocortisone efficacy and reduce calciuria) may be beneficial.