RESUMEN
A 53-year woman and her 18-year daughter presenting with bone pain, bone fractures, bone deformities and short stature were admitted to Gansu Provincial People′s Hospital in March 2021. Laboratory tests showed low blood phosphorus, low renal phosphorus threshold, normal or low blood calcium, and normal or increased PTH. The high-throughput sequencing indicated heterozygous mutations of the PHEX gene (Phosphate-regulating gene with Homology to Endopeptidases on the X chromosome) in two patients, which was not detected in other family members; finally the diagnosis of X-linked dominant hypophosphatemic rickets/osteomalacia(XLH)was confirmed for these two patients. Treated with neutral phosphorus solution and Rocaltrol, bone pain was relieved completely in the younger patient, but not for her mother due to long disease course and severe complications. Because of the large heterogeneity of the disease there are high missed diagnosis and misdiagnosis rates for XLH. In this paper a pedigree of XLH is reported with literature review.