Familial Hypophosphatemic Rickets and Hypopituitarism: A Case Report and Literature Review

Introduction: Coincided familial hypophosphatemic rickets (FHR) and Hypopituitarism is a rare condition. Growth hormone deficiency (GHD) evaluation has been advocated for refractory FHR cases, considering the possible masking effect of FHR on the former. Moreover, there has been controversial use of growth hormone as an adjunct therapy in FHR. Case Presentation: A 19-month-old girl was presented with severe growth failure, refractory to 6 months of vitamin D therapy for assumed nutritional rickets. Following detection of low serum phosphate, insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein 3 (IGFBP3), phosphaturia and positive FHR family history, she was diagnosed with concomitant FHR and hypopituitarism. Conclusions: This case highlights the fact that FHR and GHD may coexist, with possible masking effect of one on the other, thereby misleading the approach, posing large impacts on therapy, which has historically been a difficult challenge in FHR patients.