Hereditary Hypophosphatemic Rickets with Hypercalciuria

**Semantic type:** Disease or Syndrome

**Definition:** An autosomal recessive form of hypophosphatemic rickets caused by inactivating mutation(s) in the SLC34A3 gene, encoding sodium-dependent phosphate transport protein 2C, a protein involved in maintenance of inorganic phosphate concentration in the kidney. The condition is characterized by elevated 1,25-dihydroxyvitamin D (calcitriol) concentrations, resulting in increased intestinal calcium absorption and hypercalciuria. This form of hypophosphatemic rickets is also distinguished by the lack of elevated fibroblast growth factor 23 (FGF23) concentrations.

**Synonyms:** - HHRH - Hypercalciuric Hypophosphatemic Rickets - Hypophosphatemic Hypercalciuric Rickets