SUN-332: A Rare Case of Hereditary 1,25 (OH)2D Resistant Rickets

This article discusses a rare case of hereditary 1,25 (OH)2D resistant rickets, also known as vitamin D-dependent rickets type 2A (VDDR2A), which is caused by mutations in the vitamin D receptor gene. The case involves a 37-year-old male with a history of bone nonunion, multiple fractures, and some hair loss. Despite normal levels of 25-OH-vitamin D, the patient exhibited elevated 1,25 (OH)2D levels, hypocalcemia, and hypophosphatemia. Genetic testing revealed a heterozygous mutation in the VDR gene. The condition is characterized by severe rickets, bone pain, dental issues, and alopecia, and is managed with high doses of calcium and vitamin D therapy. This case underscores the importance of thorough evaluation in metabolic bone diseases and understanding vitamin D metabolism.