A distal renal tubular acidosis showing hyperammonemia and hyperlactacidemia.

distal renal tubular acidosis (dRTA) presents itself with variable clinical manifestations and often with late expressions that impact on prognosis. A 45-day-old male infant was admitted with stopping growth, difficult feeding and vomiting after meals. Clinical tests and labs revealed a type 1 renal tubular acidosis, even if the first blood tests showed ammonium and lactate increase. We had to exclude metabolic diseases before having a certain diagnosis. blood and urine investigations and genetic tests are fundamental to formulate dRTA diagnosis and to plan follow-up, according to possible phenotypic expressions of recessive and dominant autosomal forms in patients with dRTA.