The syndrome of osteopetrosis, renal acidosis and cerebral calcification in two sisters.

The syndrome of osteopetrosis associated with renal tubular acidosis and cerebral calcification, inherited as an autosomal recessive disorder, as seen in two sisters, is described. The primary defect in this rare syndrome is deficiency of carbonic anhydrase (CA) II. Significant reduction in blood levels of CA II were found in both parents and another sister, suggesting that these individuals are heterozygotic carriers.