Abnormal trace mineral metabolism in adult X-linked hypophosphatemic mice: a possible role of increased food intake.

X-linked hypophosphatemia is a human and mouse disease characterized by reduced renal tubular reabsorption of phosphate, hypophosphatemia, and dwarfism. The gene is X-linked and dominant. There have been conflicting reports in the literature regarding possible malabsorption of minerals by the intestine as well. In this study we examined the mineral status in adult X-linked hypophosphatemic (Hyp) mice by measuring trace minerals in blood, bone, muscle, liver and hair and by performing a balance study for Ca, P, Mg, Na and K. The results indicate that Hyp mice have higher than normal levels of plasma iron, bone manganese and zinc, liver iron, and muscle zinc. The trace minerals in hair were not significantly affected. The balance study showed that the content of Ca, P, Mg, Na and K of the urine and feces of normal and Hyp mice were nonsignificantly different. Hyp mice did consume more diet per gram body weight. We conclude that there is no deficiency in intestinal mineral absorption in adult Hyp mice. No tissues studied were found to have reduced trace mineral levels. In fact, where differences occurred, Hyp mice had elevated trace mineral levels in various tissues and blood. This was probably the result of the increased dietary intake per gram body weight in the Hyp mice.