A case of red cell membrane defect with distal renal tubular acidosis presenting as recurrent nephrolithiasis

Abstract

A 10-year-old male child who presented with nephrolithiasis due to distal renal tubular acidosis (dRTA) was found to have red blood cell (RBC) membrane defect as well. On review of literature, we found that both the conditions are caused by mutations in anion exchanger gene 1 (AE1) on chromosome 17 which is expressed on the RBC membrane and on the membrane of renal tubule alfa intercalated cell. It has now been shown that some AE1 mutations are responsible for causing autosomal-recessive dRTA. These patients should be either homozygous or double heterozygous with other AE1 mutations, one of which is the SAO (Southeast Asian ovalocytosis) mutation. In the latter situation, both the phenotypes, that is, dRTA and RBC membrane defect will coexist in the same patient.