MOCOS and nephrolithiasis: Among these six patients, three had causative MOCOS gene pathogenic or likely pathogenic variants; these included a 4-year-old girl, a 4-year-old boy, and a 12-year-old boy showing clinical manifestations such as bilateral nephrolithiasis and extremely low serum uric acid levels (0.1 mg/dL, 5.95 μmol/L) (Mandal et al., 2022).