FOXI1 and distal renal tubular acidosis: Biallelic FOXI1 mutations lead to a complex syndrome called distal renal tubular acidosis with deafness (dRTA; OMIM #267300) in individuals who are negative for the known causative genes, which are SLC4A1, coding for a Cl−/HCO3− exchanger, and ATP6V0A4 and ATP6V1B1, coding for vacuolar proton pumps [93].