Effect of dietary treatment on the renal tubular function in a patient with hereditary tyrosinemia.

: In a 1 1/2-month-old girl with hereditary tyrosinemia, renal tubular function studies were done. The effect of a low tyrosine and phenylalanine formula on renal tubular functions was also studied. The tubular handling of phosphorus, uric acid, beta 2-microglobulin, and amino acids was disturbed. Low urinary osmolality was also seen. Creatinine clearance was increased during a period of the standard formula. Although treatment with the low tyrosine and phenylalanine diet produces dramatic improvement in plasma tyrosine and tyrosyluria, all tubular symptoms did not revert to normal. It is possible that tubular dysfunction of hereditary tyrosinemia may be irreversible changes.