The C1QA gene encodes a component of complement C1q which along with C1r and C1s binds to antibody complexes and by that constitutes the first component of the classical complement activation pathway. Autosomal recessive deficiencies of C1q are associated with lupus erythematosus and glomerulonephritis.
6 A chains complement component C1q add to the total of 18 components of the bouquet-of-flowers-like heteromultimeric macromolecule C1q.
The three proteins A, B, and C that compose the heteromultimere C1q are mostly of extrahepatic origin. They are synthesized by immature dendritic cells, monocytes, and macrophages. The mature protein is able to bind several sproteins and to initiate the classical pathway of complement activation. Such proteins include most importantly IgG- and IgM-containing immuncomplexes and several foreign proteins on pathogens and apoptotic cells.
Clinic | Method | Carrier testing |
Turnaround | 5 days | |
Specimen type | genomic DNA |
Clinic | Method | Massive parallel sequencing |
Turnaround | 25 days | |
Specimen type | genomic DNA |
Clinic | Method | Genomic sequencing of the entire coding region |
Turnaround | 25 days | |
Specimen type | genomic DNA |
1. |
Petry F et al. (1997) Multiple identification of a particular type of hereditary C1q deficiency in the Turkish population: review of the cases and additional genetic and functional analysis. |
2. |
Diebolder CA et al. (2014) Complement is activated by IgG hexamers assembled at the cell surface. |
3. |
Stevens B et al. (2007) The classical complement cascade mediates CNS synapse elimination. |
5. |
Gilmour S et al. (1980) The conformation of subcomponent C1q of the first component of human complement. |
6. |
Bing DH et al. (1982) Fibronectin binds to the C1q component of complement. |
7. |
None (1974) A collagen-like amino acid sequence in a polypeptide chain of human C1q (a subcomponent of the first component of complement). |
8. |
Boyd Y et al. (1988) Mapping of 12 translocation breakpoints in the Xp21 region with respect to the locus for Duchenne muscular dystrophy. |
9. |
Sellar GC et al. (1991) Characterization and organization of the genes encoding the A-, B- and C-chains of human complement subcomponent C1q. The complete derived amino acid sequence of human C1q. |
10. |
Sellar GC et al. (1992) Localization of the gene cluster encoding the A, B, and C chains of human C1q to 1p34.1-1p36.3. |
11. |
Lindenbaum RH et al. (1979) Muscular dystrophy in an X; 1 translocation female suggests that Duchenne locus is on X chromosome short arm. |
12. |
Degn SE et al. (2011) Disease-causing mutations in genes of the complement system. |
13. |
Lewis MJ et al. (2009) Immunoglobulin M is required for protection against atherosclerosis in low-density lipoprotein receptor-deficient mice. |
14. |
Botto M et al. (1998) Homozygous C1q deficiency causes glomerulonephritis associated with multiple apoptotic bodies. |
15. |
Topaloglu R et al. (1996) Molecular basis of hereditary C1q deficiency associated with SLE and IgA nephropathy in a Turkish family. |
16. |
Orphanet article Orphanet ID 221162 |
17. |
NCBI article NCBI 712 |
18. |
OMIM.ORG article Omim 120550 |
19. |
Wikipedia article Wikipedia EN (C1QA) |