Autosomal hypophosphataemic bone disease responds to 1,25-(OH)2D3.
We diagnosed non X-linked hypophosphataemic bone disease in a 38-month-old girl. Findings included: genu varum, shortened stature, fasting hypophosphataemia (2.3-2.5 mg/100 ml; 0.74-0.81 mmol/l), diminished theoretical renal threshold for phosphate (TmP/GFR), and osteomalacia without rickets. One patient (the father) had fasting hypophosphataemia (2.3-2.7 mg/100 ml; 0.74-0.87 mmol/l) and low TmP/GFR without osteomalacia or shortened stature. Treatment of the girl with 1,25-(OH)2D3 (1 microgram a day) raised the level of serum phosphorus, improved tubular reabsorption of phosphate, and healed the bone deformity; this combination of responses is not present in X-linked hypophosphataemia. There was no correction of hypophosphataemia or TmP/GFR with 1,25-(OH)2D3 treatment (1-3 micrograms a day) in the father.
D000328:Adult; D001851:Bone Diseases, Metabolic / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D002675:Child, Preschool; D004100:Dihydroxycholecalciferols / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000627:therapeutic use*; D007015:Hypophosphatemia, Familial / Q000188:drug therapy* / Q000378:metabolism; D007684:Kidney Tubules / Q000378:metabolism; D008297:Male; D010710:Phosphates / Q000378:metabolism; D010758:Phosphorus / Q000097:blood
D004100:Dihydroxycholecalciferols; D006887:Hydroxycholecalciferols; D010710:Phosphates; D010758:Phosphorus