C4A complement C4A (Chido/Rodgers blood group)
Gene ID: 720, updated on 28-Oct-2024Gene type: protein coding
Also known as: C4; RG; C4S; CO4; C4A2; C4A3; C4A4; C4A6; C4AD; CPAMD2
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- Go to complete Gene record for C4A
- Go to Variation Viewer for C4A variants
Summary
This gene encodes the acidic form of complement factor 4, part of the classical activation pathway. The protein is expressed as a single chain precursor which is proteolytically cleaved into a trimer of alpha, beta, and gamma chains prior to secretion. The trimer provides a surface for interaction between the antigen-antibody complex and other complement components. The alpha chain is cleaved to release C4 anaphylatoxin, an antimicrobial peptide and a mediator of local inflammation. Deficiency of this protein is associated with systemic lupus erythematosus and type I diabetes mellitus. This gene localizes to the major histocompatibility complex (MHC) class III region on chromosome 6. Varying haplotypes of this gene cluster exist, such that individuals may have 1, 2, or 3 copies of this gene. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2014]
Associated conditions
See all available tests in GTR for this gene
| Description | Tests |
|---|---|
| Blood group, Chido/Rodgers system | See labs |
| Complement component 4a deficiency | See labs |
| Genome-wide association study for serum complement C3 and C4 levels in healthy Chinese subjects. GeneReviews: Not available | |
| Identification of 23 new prostate cancer susceptibility loci using the iCOGS custom genotyping array. GeneReviews: Not available |
Genomic context
- Location:
- 6p21.33
- Sequence:
- Chromosome: 6; NC_000006.12 (31982057..32002681)
- Total number of exons:
- 41
Variation
| Resource | Links for this gene |
|---|---|
| ClinVar | Variants reported to ClinVar |
| dbVar | Studies and variants |
| SNP | Variation Viewer for C4A variants |
| Genome viewer | Explore NCBI-annotated and select non-NCBI annotated genome assemblies |
- C4A database
- ClinVarRelated medical variations
- dbVarLink from Gene to dbVar
- MedGenRelated information in MedGen
- OMIMLink to related OMIM entry
- PubMed (OMIM)Gene links to PubMed derived from omim_pubmed_cited links
- RefSeq RNAsLink to Nucleotide RefSeq RNAs
- RefSeqGeneLink to Nucleotide RefSeqGenes
- Variation ViewerRelated Variants
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