Hypophosphatemic bone disease needs lifelong treatment

Hypophosphatemic bone disease (HBD) is a phosphopenic rickets accompanied by hypophosphatemia, hyperphosphaturia with no roentgenographic evidence of rickets. This is the report of a girl and his father who have this disorder. A 7.2-yr-old girl visited the hospital because of short stature. Her height SDS (HSDS) was - 3.3 and her weight below 5th percentile. She did not have any bone deformity both clinically and radiologically. Her serum phosphorus was 2.3 mg/dL (normal for age, 4.5 – 6.5) and alkaline phosphatase 455 IU/L (normal up to 440). Fractional excretion of phosphorus (FEP) was 23.7% (normal <15%), Maximum tubular reabsorption of phosphate/glomerular filtration rate (TmP/GFR) was 1.7 mg/dL, PTH 46 pg/mL (normal up to 80 pg/mL). Three years after treatment, her HSDS was –2.3, serum phosphorus 4.3 mg/dL, and AlkP 917 IU/L (180-1200). His father, at the age of 52, had a height of 158.5 cm and weighed 64 kg. He had been suffering from severe bone pain in spine and limbs for more than 10 years. Clinically, he had no remarkable bone deformity but had to take different anti-inflammatory agents for relieving his pains and could not stand and walk without crutches. His serum phosphorus was 1.7 mg/dL, AlkP 624 (normal: 70-306), PTH 47 pg/mL (normal: 40 - 100). Before treatment (during phosphorus depletion) FEP was 10% and TmP/GFR was 3 mg/dL and after 2 months of treatment reached 62.8% and 0.9 mg/dL respectively. After 5 months of treatment for father, bone pains were relieved, all sedatives were discontinued and he could walk and do exercise independently. He has been doing well for 3 years but he suffers from paresthesia of his hands due to cervical spinal cord compression. HBD can cause short stature in children and if its diagnosis is missed will produce disability at adulthood.