[Accidentally diagnosed distal renal tubular acidosis with nephrocalcinosis - a case report].

Distal renal tubular acidosis is a defect of acidification of urine in distal tubule. Full-blown form is characterized by polyuria, growth deficiency, nephrolithiasis or nephrocalcinosis. Mutations in genes encoding Cl-/HCO3 - exchanger (autosomal dominant) or H+-ATPase (autosomal recessive) are the most frequent in children.In a boy aged 2,5 years, healthy, with proper development, metabolic acidosis with hyperchloremia, hypokalaemia, normal glomerular filtration rate and alkaline urine was discovered during hospitalization because of pneumonia. USG showed normal length kidney with nephrocalcinosis type IIB. The family history revealed nephrocalcinosis on the part of the boy's father. He also had metabolic acidosis in blood gas test. Genetic test in a boy and his father showed mutation of SLC4A1(17q21-q22) gene encoding Cl-/HCO3 - exchanger. The boy was treated with 8,4% NaHCO3 - orally (1mEq/kg/24h) and KCl (0,3 mEq/kg/24h). We obtained normalization of blood gas test and potassium concentration.Every child, with accidentally discovered metabolic acidosis, even with normal development, should be diagnosed in case of renal tubular acidosis. Electrolytes, gas blood test, urinalysis and USG are needed in the closest family members of child with diagnosed renal tubular acidosis.