» Articles » PMID: 12224044

Determining the One, Two, Three, or Four Long and Short Loci of Human Complement C4 in a Major Histocompatibility Complex Haplotype Encoding C4A or C4B Proteins

Overview
Journal Am J Hum Genet
Publisher Cell Press
Specialty Genetics
Date 2002 Sep 12
PMID 12224044
Citations 26
Authors
Affiliations
Soon will be listed here.
Abstract

The complex genetics of human complement C4 with unusually frequent variations in the size and number of C4A and C4B, as well as their neighboring genes, in the major histocompatibility complex has been a hurdle for accurate epidemiological studies of diseases associated with C4. A comprehensive series of novel or improved techniques has been developed to determine the total gene number of C4 and the relative dosages of C4A and C4B in a diploid genome. These techniques include (1) definitive genomic restriction-fragment-length polymorphisms (RFLPs) based on the discrete duplication patterns of the RCCX (RP-C4-CYP21-TNX) modules and on the specific nucleotide changes for C4A and C4B isotypes; (2) module-specific PCR to give information on the total number of C4 genes by comparing the relative quantities of RP1- or TNXB-specific fragments with TNXA-RP2 fragments; (3) labeled-primer single-cycle DNA polymerization procedure of amplified C4d genomic DNA for diagnostic RFLP analysis of C4A and C4B; and (4) a highly reproducible long-range-mapping method that employs PmeI-digested genomic DNA for pulsed-field gel electrophoresis, to yield precise information on the number of long and short C4 genes in a haplotype. Applications of these vigorously tested techniques may clarify the roles that human C4A and C4B gene-dosage variations play in infectious and autoimmune diseases.

Citing Articles

The complement system and human autoimmune diseases.

Coss S, Zhou D, Chua G, Aziz R, Hoffman R, Wu Y J Autoimmun. 2022; 137:102979.

PMID: 36535812 PMC: 10276174. DOI: 10.1016/j.jaut.2022.102979.


Human Complement C4B Allotypes and Deficiencies in Selected Cases With Autoimmune Diseases.

Zhou D, Rudnicki M, Chua G, Lawrance S, Zhou B, Drew J Front Immunol. 2021; 12:739430.

PMID: 34764957 PMC: 8577214. DOI: 10.3389/fimmu.2021.739430.


Genes and Pseudogenes: Complexity of the RCCX Locus and Disease.

Carrozza C, Foca L, De Paolis E, Concolino P Front Endocrinol (Lausanne). 2021; 12:709758.

PMID: 34394006 PMC: 8362596. DOI: 10.3389/fendo.2021.709758.


Mendelian randomization integrating GWAS and eQTL data revealed genes pleiotropically associated with major depressive disorder.

Yang H, Liu D, Zhao C, Feng B, Lu W, Yang X Transl Psychiatry. 2021; 11(1):225.

PMID: 33866329 PMC: 8053199. DOI: 10.1038/s41398-021-01348-0.


Elevated serum complement levels and higher gene copy number of complement are associated with hypertension and effective response to statin therapy in childhood-onset systemic lupus erythematosus (SLE).

Mulvihill E, Ardoin S, Thompson S, Zhou B, Yu G, King E Lupus Sci Med. 2019; 6(1):e000333.

PMID: 31448126 PMC: 6687033. DOI: 10.1136/lupus-2019-000333.


References
1.
Zhang W, Degli-Esposti M, Cobain T, Cameron P, Christiansen F, Dawkins R . Differences in gene copy number carried by different MHC ancestral haplotypes. Quantitation after physical separation of haplotypes by pulsed field gel electrophoresis. J Exp Med. 1990; 171(6):2101-14. PMC: 2187943. DOI: 10.1084/jem.171.6.2101. View

2.
Collier S, Sinnott P, Dyer P, Price D, Harris R, Strachan T . Pulsed field gel electrophoresis identifies a high degree of variability in the number of tandem 21-hydroxylase and complement C4 gene repeats in 21-hydroxylase deficiency haplotypes. EMBO J. 1989; 8(5):1393-402. PMC: 400966. DOI: 10.1002/j.1460-2075.1989.tb03520.x. View

3.
Wild G, Watkins J, Ward A, Hughes P, Hume A, ROWELL N . C4a anaphylatoxin levels as an indicator of disease activity in systemic lupus erythematosus. Clin Exp Immunol. 1990; 80(2):167-70. PMC: 1535284. DOI: 10.1111/j.1365-2249.1990.tb05227.x. View

4.
Gitelman S, Bristow J, Miller W . Mechanism and consequences of the duplication of the human C4/P450c21/gene X locus. Mol Cell Biol. 1992; 12(5):2124-34. PMC: 364384. DOI: 10.1128/mcb.12.5.2124-2134.1992. View

5.
Feucht H, SCHNEEBERGER H, Hillebrand G, Burkhardt K, Weiss M, Riethmuller G . Capillary deposition of C4d complement fragment and early renal graft loss. Kidney Int. 1993; 43(6):1333-8. DOI: 10.1038/ki.1993.187. View