Idiopathic Hypercalcuria in a Child.

Hypercalcuria occurs in many conditions including hyperparathyroidism, vitamin D poisoning, sarcoid, and renal tubular acidosis. In adult patients with renal calculi, the urinary calcium excretion may be high for no apparent reason. Such patients include (a) those described by Hodgkinson and Pyrah (1958), hypercalcuria being the only abnormal tinding, and (b) those described by Henneman, Benedict, Forbes, and Dudley (1958): in this group the patients, who were all males, had a low serum phosphorus without hypercalcaemia in addition to hypercalcuria. Hodgkinson and Pyrah (1958) showed that hypercalcuria was associated with an increased incidence of stone formation, and demonstrated that hypercalcuria and the incidence of renal calculi were higher in men than in women. Four dwarfed children with hypercalcuria have recently been described by Royer (1962). The present report describes a 6-year-old white English boy (E.B.) who had nephrocalcinosis. He was found to have hypercalcuria of the 'idiopathic' variety as determined by systematic exclusion of disorders known to cause hypercalcuria. Hypercalcuria was also demonstrated in his father and brother but not in his mother. Henneman, Dempsey, Carroll, and Albright (1956) suggested that sodium phytate might be of use in the treatment of hypercalcuria, since it was known that 2 905 g. ofsodium phytate (Na12C6H6O24P6 38H20) would precipitate 0 306 g. calcium (Hoff-J0rgensen, 1946; Hoff-J0rgensen, Andersen, and Nielsen, 1946). The treatment was used successfully by Henneman et al. (1958), who found that in combination with a high fluid intake and removal of cheese and milk from the diet, sodium phytate decreased the hypercalcuria and prevented the growth of renal stones and their recurrence. Hoff-J0rgensen et al. (1946) had already shown that the administration of sodium phytate to children led to a reduction in the absorption and retention of calcium, though changes in the urine were not very striking or consistent. It