,11 Individuals with heterozygous pathogenic CYP24A1 variants exhibit an intermediary phenotype characterized by recurrent calcium nephrolithiasis, normocalcemic hypercalciuria, high-normal 1,25(OH)2 vitamin D3, and low-normal PTH, a constellation typically encountered in idiopathic hypercalciuria, suggesting a gene dosage effect for pathogenic CYP24A1 variants.10 Here, CYP24A1 is linked to idiopathic hypercalciuria.