Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a rare autosomal recessive disorder characterized by hypophosphatemia, hypercalciuria, and recurrent nephrolithiasis, often resulting in rickets and osteomalacia.1 Mutations in the SLC34A3, which encodes the renal sodium-phosphate cotransporter NaPi-IIc, are the leading cause of HHRH. A case study of a 30-year-old female patient revealed she had compound heterozygous mutations in SLC34A3, including a novel intronic mutation, impacting gene splicing and reducing protein production. This underscores the critical role of SLC34A3 in HHRH and broadens the understanding of its genotypic and phenotypic diversity. Genetic diagnosis is crucial in identifying this rare disease, as active vitamin D is contraindicated in HHRH patients due to the associated hypercalciuria and nephrolithiasis.