Carbonic anhydrase II deficiency : Osteopetrosis

Carbonic anhydrase (CA) isoenzyme II deficiency -formerly called the syndrome of osteopetrosis with renal tubular acidosis and cerebral calcification-is an autosomal recessive «inborn error of metabolism» that has disclosed important insight concerning osteoclast function. Nearly 50 cases have been described, predominantly from the Middle East and Mediterranean region. It is discovered late in infancy or early in childhood through developmental delay, short stature, fracture, weakness, cranial nerve compression, dental malocclusion, and/or mental subnormality. Typical radiographic features of osteopetrosis are present, and histopathologic study of the iliac crest reveals unresorbed calcified primary spongiosa