摘要

The RCCX module on chromosome 6p21.3 has 3 possible forms: monomodular, bimodular, and trimodular. Chromosomes with 4 RCCX modules are very rare. In the monomodule, most of the CYP21A1P genes do not exist. However, haplotypes of the RCCX module with more than one CYP21A2 gene were observed. Obviously, the gene located downstream of the XA gene can possibly include the CYP21A2 as well as the CYP21A1P gene.