Natural History of Patients With PH3 and a History of Stone Events

Key inclusion criteria * Genetically confirmed PH3 * For participants at least 2 years of age, history of stone events (defined as presence of calcifications in the urinary tract and/or kidney, their relative location, and the number and size of stones) during the last 3 years and/or presence of pre-existing stones detected by renal ultrasound at Screening * Uox ≥ 0.7 mmol/24 hours (adjusted per 1.73 m2 BSA in participants \< 18 years of age) OR if not able to collect 24-hour urine, average spot Uox to creatinine ratio at Screening above the 95th percentile for age: * \> 220 mmol/mol in participants \< 6 months * \> 170 mmol/mol in participants from 6 months to \< 12 months * \> 130 mmol/mol in participants 12 months to \< 2 years * \> 100 mmol/mol in participants from 2 to \< 3 years and * \> 80 mmol/mol in participants from 3 to 5 years * eGFR at Screening ≥ 30 mL/min or for infants aged less than 12 months, serum creatinine below the 97th percentile of a healthy population Key Exclusion Criteria: * Prior or planned liver transplant within study period * Currently receiving dialysis or anticipating dialysis during study period * Unwillingness to comply with study procedures