A rare presentation of autosomal recessive proximal renal tubular acidosis

Abstract

Proximal renal tubular acidosis (pRTA) is characterised by an inability of the kidneys to reabsorb bicarbonate from the proximal convoluted tubule leading to urinary loss of bicarbonate ions causing metabolic acidosis. It can present as an isolated pRTA or be associated with Fanconi syndrome. Isolated inherited pRTA is exceedingly rare. The inheritance can be autosomal dominant, autosomal recessive (AR), or sporadic. The AR form is linked to a SLC4A4 (NBCe1) mutation and is associated with glaucoma, cataract, band keratopathy, mental and growth retardation requiring lifelong alkali therapy and ocular care. The prognosis is good although extra-renal symptoms may persist and ocular abnormalities may progress with age. Here, we report a rare case of congenital glaucoma associated with cataracts, band keratopathy, growth retardation, and mental retardation in a young female having isolated AR pRTA with SLC4A4 gene mutation.