Autosomal Dominant Distal Renal Tubular Acidosis

A rare inherited form of distal renal tubular acidosis (dRTA) characterized by hyperchloremic metabolic acidosis often but not always associated with hypokalemia.

Epidemiology

The prevalence is unknown.

Clinical description

Disease onset occurs in adolescence or adulthood and initial manifestations can include polyuria, polydipsia, muscle weakness and fatigue. Osteomalacia or osteopenia can occur due to calcium salt loss from the bones. Hypercalciuria, nephrolithiasis and nephrocalcinosis may result from long term chronic metabolic acidosis. Renal failure has not been described.

Etiology

AD dRTA is due to mutations in the SLC4A1 gene (17q21.31) encoding the band 3 anion transport protein (AE1). This protein is found in the alpha-intercalated distal tubular cells and red blood cell membranes. Mutations in the SLC4A1 gene show a pleiotrophic effect that result in two distinct phenotypes: dRTA or red cell dysmorphologies (hereditary spherocytosis or Southeast Asian ovalocytosis) (see these terms).

Genetic counseling

This disease is inherited in an autosomal dominant manner and genetic counseling is possible.