A POINT MUTATION IN EXON-3 (HIS-107-]TYR) IN 2 UNRELATED JAPANESE PATIENTS WITH CARBONIC-ANHYDRASE-II DEFICIENCY WITH CENTRAL-NERVOUS-SYSTEM INVOLVEMENT

We have analyzed two unrelated Japanese patients with carbonic anhydra se II deficiency born to consanguineous parents. We have identified th e same mutation as that reported to be homozygous in a Belgian family and compound heterozygous in an American family. It comprises to C-to- T transition that results in the amino acid substitution of Tyr (TAT) for His (CAT) at position 107. This point mutation creates an AccI sit e that can be conveniently screened by the polymerase chain reaction/r estriction fragment length polymorphism method using a restriction enz yme for gene tracking, Our patients exhibit severe mental retardation, not seen in the Belgian and American patients.