Advances in human immunoglobulin allotypes.

Monoclonal anti-Rh's and monoclonal anti-Gm's are now available, permitting a more precise serological determination of the human allotypes. Several Gm allotypes can be determined at the gene level, without resort to serological reagents. PCR, subclass-specific amplification and allele-specific probes are used. Many RFLPs of the human IgH C- and V-region genes have now been defined. More than 10(6) variant haplotypes of the so-called constant part of the Ig chain are possible because more than 20 polymorphic sites are known. A schematic physical map of the human IgHC gene cluster is presented.