title: A genetic marker of human IgE heavy chains, Em(1).
abstract: A monoclonal anti-IgE antibody was obtained that reacted with some IgE myeloma proteins and with all but a few normal sera. Family studies proved that a genetic marker of IgE had been detected. This allotype, called Em(1), segregates in association with certain Gm-Am haplotypes. The available quantitative evidence warrants the conclusion that human IgE has genetic variants, but no subclasses. Samples from various populations of five continents, representative for the respective prevalent Gm-Am haplotypes, were tested for Em(1). Em(1) was absent mainly in haplotypes carrying A2m(2) and G2m(n). These closely linked genes are located in a chromosomal region that comprises the gamma 2-gamma 4-epsilon-alpha 2 CH genes. A hypothesis for the generation of Em(1) is given.
mesh_terms: D000349:Africa; D000569:Americas; D000818:Animals; D001208:Asia; D001315:Australia; D002648:Child; D005060:Europe; D005260:Female; D008040:Genetic Linkage; D005828:Genetics, Population; D006071:Gorilla gorilla; D006238:Haploidy; D006801:Humans; D007070:Immunoglobulin A / Q000235:genetics; D007126:Immunoglobulin Allotypes / Q000235:genetics*; D007073:Immunoglobulin E / Q000235:genetics*; D007074:Immunoglobulin G / Q000235:genetics; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D008297:Male; D002679:Pan troglodytes; D011148:Pongo pygmaeus
chemical_list: D007070:Immunoglobulin A; D007126:Immunoglobulin Allotypes; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007073:Immunoglobulin E