[Congenital metabolic disorder].

In children, tubulo-interstitial nephritis (TIN) is often associated with obstructive uropathy, metabolic disorders or hereditary diseases. The author reviewed congenital metabolic disorders (Fanconi syndrome, cystinosis, Lowe's syndrome, and hyperoxaluria) as causes of TIN. The Fanconi syndrome is caused by numerous disorders including cystinosis and Lowe's syndrome, and refers to a dysfunction of the proximal tubule leading to excessive urinary excretion of amino acids, glucose, phosphate, bicarbonate, etc. Prognosis of idiopathic Fanconi syndrome is not so bad if electrofluid balance is well maintained. On the other hand, prognosis of the infantile type of cystinosis, Lowe's syndrome, or hyperoxaluria "type 1" is poor. The pathophysiology of each disease should be fully understood for early diagnosis and treatment.