CA8 was first called CA-related protein since there is a sequence similarity to other identified carbonic anhydrase genes. Still， this protein has no carbonic anhydrase activity - the reversible hydration of carbon dioxide. CA8 still holds a carbonic anhydrase designation due to obvious sequence similarity to other members of the carbonic anhydrase gene family. Mutations in CA8 result in cerebellar ataxia mental retardation and dysequilibrium syndrome type 3（CMARQ3).
