title: Copy number polymorphisms are not a common feature of innate immune genes.
abstract: Extensive copy number polymorphism was recently reported for innate immunity-related alpha-defensin genes DEFA1 and DEFA3 and beta-defensin genes DEFB4, DEFB103, and DEFB104. To establish whether such polymorphisms are a common feature of innate immune genes we used quantitative real-time PCR to determine the copy numbers of seven genes whose products have important innate immune functions. The genes encoding lysozyme, lactoferrin, cathelicidin antimicrobial peptide (hCAP18/LL-37), cathepsin G, bactericidal/permeability-increasing protein, azurocidin (CAP37/heparin-binding protein), and neutrophil elastase were each found to be single copy per haploid genome. These findings, along with the recent observation that defensin genes DEFA4, DEFA5, DEFA6, and DEFB1 are single copy, suggest that copy number polymorphisms are not a common feature of the innate immune genome but are restricted to a small subset of innate immunity-related genes.
authors.affiliation: Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1690, USA. rlinzmeier@mednet.ucla.edu
authors.forename: Rose M
authors.initials: RM
authors.lastname: Linzmeier
authors.forename: Tomas
authors.initials: T
authors.lastname: Ganz
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000235:genetics; D001798:Blood Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D056649:Cathepsin G; D002403:Cathepsins / Q000235:genetics; D018628:Gene Dosage; D015894:Genome, Human; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics*; D007781:Lactoferrin / Q000235:genetics; D019272:Leukocyte Elastase / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics; D009113:Muramidase / Q000235:genetics; D009195:Peroxidase / Q000235:genetics; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012697:Serine Endopeptidases / Q000235:genetics; D054804:Cathelicidins
chemical_list: C062991:AZU1 protein, human; D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D002352:Carrier Proteins; D008565:Membrane Proteins; C021623:bactericidal permeability increasing protein; D009195:Peroxidase; D009113:Muramidase; D002403:Cathepsins; D007781:Lactoferrin; D012697:Serine Endopeptidases; C534094:CTSG protein, human; D056649:Cathepsin G; D019272:Leukocyte Elastase; D054804:Cathelicidins