Unit

UNIT 13.8 Human Complement Components C4A and C4B Genetic Diversities: Complex Genotypes and Phenotypes

  1. Erwin K. Chung,
  2. Yee Ling Wu,
  3. Yan Yang,
  4. Bi Zhou,
  5. C. Yung Yu

Published Online: 1 SEP 2005

DOI: 10.1002/0471142735.im1308s68

Current Protocols in Immunology

Current Protocols in Immunology

How to Cite

Chung, E. K., Wu, Y. L., Yang, Y., Zhou, B. and Yu, C. Y. 2005. Human Complement Components C4A and C4B Genetic Diversities: Complex Genotypes and Phenotypes. Current Protocols in Immunology. 68:13.8:13.8.1–13.8.36.

Author Information

  1. Columbus Children's Research Institute and The Ohio State University, Columbus, Ohio

Publication History

  1. Published Online: 1 SEP 2005
  2. Published Print: AUG 2005

Abstract

This unit describes methods that can accurately determine the genotypes and phenotypes of human complement components C4A and C4B. Specifically, they allow investigators to determine how many C4 genes are present in a diploid genome of a human subject and to quantify how many of them encode C4A proteins and how many of them encode C4B proteins. In addition, methods to determine how many long and short C4 genes are present in a diploid genome of a subject are described together with experimental strategies to determine haplotypes and order or configuration of these genes in the MHC. Finally, methods to assess the degree of polymorphism in C4A and C4B proteins and whether low protein levels of plasma C4 may be caused by low C4 gene dosages and/or by mutant C4 genes.

Keywords:

  • C4 polygenic variation;
  • C4 genes;
  • endogenous retrovirus HERV-K(C4);
  • RP-C4-CYP21-TNX (RCCX) modules;
  • C4A/C4B allotypes;
  • Ch1/Rg1 blood group antigenic determinants;
  • MHC complement gene cluster (MCGC);
  • complement C2 deficiency;
  • labeled-primer single-cycle DNA polymerization (LSP);
  • module-specific PCR