DNA polymorphism in the 5' flanking region of the human carbonic anhydrase II gene on chromosome 8.

A restriction-fragment-length polymorphism (RFLP) is described which is associated with the human carbonic anhydrase II gene (CA2) that codes for one of the three genetically distinct carbonic anhydrase isozymes, CA I, CA II, and CA III. The isolated DNA was cleaved with several restriction enzymes and subjected to Southern blot hybridization analysis using a DNA probe containing the 5' end of the human CA II gene. A two allele RFLP which was detected with the restriction endonuclease, Taq I, is expressed phenotypically on Southern blots as either a 5.4 kilobase (kb) fragment or as 4.0 and 1.4kb fragments. These fragments result from the presence or absence of a Taq I recognition site in the 5' flanking region approximately 1.0kb from the initiation codon of the CA II gene. Segregation analysis showed that the alleles are inherited in a Mendelian fashion, with a frequency of 50%.