Pseudoautosomal genes in man.

MIC2, which encodes the 12E7 antigen, is the only well-defined pseudoautosomal gene in man. We have isolated cDNA and genomic sequences corresponding to MIC2 and have produced monoclonal antibodies reacting with the 12E7 antigen. These molecular tools have been used to investigate the genetics and biochemistry of the MIC2 system. Recent results suggest that MIC2 is the most proximal of the currently defined pseudoautosomal markers and that the escape of MIC2 from X-inactivation may be intrinsic to an associated HTF island found at the 5' end of the gene. Investigation of the inter-relationship between MIC2 and the XG locus has led us to postulate the existence of a second pseudoautosomal gene in man.