Mutations to the V-ATPase 'a4' or 'B1' isoforms result in distal renal tubular acidosis, a condition that leads to metabolic acidosis, in some cases with sensorineural deafness.
Renal tubular acidosis failure of HCO3- resorption(i.e., proximal renal tubular acidosis, or overdose of carbonic anhydrase inhibitor) or failure of H+ secretion (i.e. in distal renal tubular acidosis)
Adolph Kussmaul, who introduced the term, referred to breathing when metabolic acidosis was sufficiently severe for the respiratory rate to be normal or reduced.
Congenital chloride diarrhea - rare for being a diarrhea that causes alkalosis instead of acidosis.
Trauma triad of death, the fatal combination of hypothermia, acidosis and coagulopathy