Hereditary distal renal tubular acidosis with chronic granulomatous disease: a rare coincidence.

The primary defect in distal renal tubular acidosis (dRTA) is impaired H⁺ ion secretion in the distal nephron, resulting in a normal anion gap metabolic acidosis. The solute carrier family 4-member 1 (SLC4A1) gene encodes the erythroid and renal anion exchanger 1 (AE1) protein for chloride-bicarbonate exchange. Mutations in the gene can result in hereditary dRTA, red blood cell membrane defect, and hemolytic anemia. Chronic granulomatous disease (CGD) is a rare primary immunodeficiency syndrome caused by NADPH oxidase deficiency, leading to impaired neutrophil and phagocyte function, and thus predisposing the patient to multiple bacterial infections. Melioidosis is a rare infection caused by Burkholderia pseudomallei and is often linked to CGD. Here we present an interesting case of an 8-year-old girl with melioidosis secondary to CGD. Also, she had nephrocalcinosis, metabolic acidosis, hypercalciuria, and anemia. The simultaneous presence of distal RTA (Pathogenic homozygous SLC4A1 mutation on whole exome sequencing) and CGD has not been reported previously and reiterates the importance of detailed clinical evaluation combined with investigations for the long-term management of such complex cases.