C1QA, Official Symbol C1QAprovided by HGNC Official Full Name complement C1q A chainprovided by HGNC Primary source HGNC:HGNC:1241 See related Ensembl:ENSG00000173372 MIM:120550; AllianceGenome:HGNC:1241 Gene type protein coding RefSeq status REVIEWED Organism Homo sapiens Lineage Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo Also known as C1QD1 Summary This gene encodes the A-chain polypeptide of serum complement subcomponent C1q, which associates with C1r and C1s to yield the first component of the serum complement system. C1q deficiency is associated with lupus erythematosus and glomerulonephritis. C1q is composed of 18 polypeptide chains which include 6 A-chains, 6 B-chains, and 6 C-chains. Each chain contains an N-terminal collagen-like region and a C-terminal C1q globular domain. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Nov 2016] Expression Broad expression in spleen (RPKM 445.5), lymph node (RPKM 179.4) and 16 other tissues See more Orthologs mouse all