Carbonic anhydrase II deficiency in a Japanese patient produced by a nonsense mutation (TAT →TAG) at Tyr-40 in exon 2, (Y40X)

The carbonic anhydrase II deficiency syndrome is an autosomal recessive disorder that produces osteopetrosis, renal tubular acidosis, and cerebral calcification. Other features include mental retardation, growth failure, and dental malocclusion. More than 30 cases of this disorder, termed carbonic anhydrase II deficiency syndrome, have been diagnosed from a variety of ethnic background, including Italian, German, Belgian, French, Hispanic, Afro-American, and Arabian. We reported a 23-year-old woman with carbonic anhydrase II deficiency syndrome in Japanese population. This paper describes the gene mutation in this patient, who had renal tubular acidosis, osteopetrosis, symmetrical cerebral calcification and mental retardation.