Renal Transplantation in Hypophosphatemia With Vitamin D-Resistant Rickets

Abstract

Familial hypophosphatemia is a hereditary disorder with X-linked dominant inheritance and a high degree of penetrance.¹Some, but not all, affected individuals early in life develop rickets that is highly resistant to vitamin D administration. The most characteristic feature of the disease is phosphaturia, which results from a tubular defect in the parathyroid hormone (PTH)-sensitive component of tubular phosphate reabsorption.²Untreated hypophosphatemic individuals may have normal PTH concentrations in the blood, but are unresponsive to it.³The recent demonstration that inorganic phosphate uptake by the intestinal mucosa is also impaired in affected individuals suggests a generalized metabolic defect.⁴A unique opportunity to transplant a sister's normal kidney to a severely affected man has provided additional support for this possibility. <h3>Patient Summary</h3> This patient was the fifth child of normal parents. His mother was short in stature, but was never known to have bone disease. His father