Novel compound heterozygous ATP6V0A4 mutations in an infant with distal renal tubular acidosis.

A Japanese infant presenting with vomiting, failure to thrive, metabolic acidosis, and hyperammonemia was finally diagnosed with autosomal recessive distal renal tubular acidosis (dRTA). Hyperchloremic metabolic acidosis, hypokalemia, a normal serum anion gap, a positive urine anion gap, nephrocalcinosis, and high urine pH despite systemic acidemia were consistent with the cardinal manifestations in dRTA. Mutational analysis of the ATP6V0A4 gene revealed novel compound heterozygous mutations: Ile549fsX580 and Ile557Leu558del.