Changing patterns of femoral and skeletal mineralization during growth in juvenile X-linked hypophosphatemic mice.

Femoral and skeletal mineralization were studied in normal and X-linked hypophosphatemic (Hyp) mice from birth to 13 weeks of age. Although the Hyp mice were continuously hypophosphatemic, their body weight, trunk length, femoral ash weight and total body calcium content were not significantly affected through 3 weeks of age. Tail length and femoral length were depressed by less than 10%. Between 3 and 7 weeks of age the normal mice continued their rapid growth, but there was little further lengthening of the femur or tail in the Hyp mice; body weight and trunk length fell behind the normals; and there was no further accumulation of femoral ash weight or total body calcium and little increase in total body phosphate. After 7 weeks of age the Hyp mice resumed accumulation of femoral and total body mineral.