Iron Supplementation Associated With Loss of Phenotype in Autosomal Dominant Hypophosphatemic Rickets

Context: Autosomal dominant hypophosphatemic rickets (ADHR) is the only hereditary disorder of renal phosphate wasting in which patients may regain the ability to conserve phosphate. Low iron status plays a role in the pathophysiology of ADHR. Objective: This study reports of a girl with ADHR, iron deficiency, and a paternal history of hypophosphatemic rickets that resolved without treatment. The girl's biochemical phenotype resolved with iron supplementation. Subjects: A 26-month-old girl presented with typical features of hypophosphatemic rickets, short stature (79 cm; −2.82 SDS), and iron deficiency. Treatment with elemental phosphorus and calcitriol improved her biochemical profile and resolved the rickets. The girl's father had presented with rickets at age 11 months but never received medication. His final height was reduced (154.3 cm; −3.51 SDS), he had undergone corrective leg surgery and had an adult normal phosphate, fibroblast growth factor 23, and iron status. Father and daughter were found to...