• 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]
  

C1QA (Complement C1q A Chain) is a Protein Coding gene. Diseases associated with C1QA include C1q Deficiency 1 and Immunodeficiency Due To A Classical Component Pathway Complement Deficiency. Among its related pathways are Complement cascade and Initial triggering of complement. An important paralog of this gene is C1QB.