Hypophosphatemic Rickets (Vitamin D-Resistant Rickets) By Christopher J LaRosa, MD, Perelman School of Medicine at The University of Pennsylvania Reviewed / Revised Dec 2022 View Patient Education Pathophysiology Symptoms and Signs Diagnosis Treatment Key Points More Information Topic Resources Forms of Hereditary Hypophosphate... Hypophosphatemic rickets is a genetic disorder characterized by hypophosphatemia, defective intestinal absorption of calcium, and rickets or osteomalacia unresponsive to vitamin D. It is usually hereditary.