Deficiency complement factor I (Complement factor I deficiency) - Gen CFI.

Deficiency of complement factor I is a disorder that affects the immune system. Affected individuals are prone to recurrent infections, such as infections of the upper respiratory tract, ears, skin and urinary tract. They can also get more serious infections such as pneumonia, meningitis and sepsis, which may be potentially affected mortales.Algunas have a kidney disorder called glomerulonephritis with isolated C3 deposits. A deficiency of complement factor I may also be associated with autoimmune disorders such as rheumatoid arthritis or systemic lupus erythematosus (SLE).

This disease is due to mutations in the CFI gene, located on the long arm of chromosome 4 (4q25). This gene encodes a protein called Factor I of the complement system, which helps to regulate a part of the body 's immune response. The complement system is a group of proteins that act together to foreign invaders (such as bacteria and viruses), triggering inflammation and removing cell debris and tissue. This system must be carefully regulated so as to be directed only against unwanted elements and not attack healthy cells in the body. The complement factor I and several related proteins protect healthy cells by inactivation of the complement system when not needed.

They have identified at least 10 mutations in the CFI gene in people with factor I deficiency complemento.Las CFI mutations in the gene give rise to an abnormal complement factor I, non - functional or absent. Deficiency of this functional protein causes uncontrolled activation of the complement system. This unregulated activity of the complement system decreases the concentrations of other proteins called complement C3, which reduces the immune system 's ability to fight infection. In addition, the immune system may operate improperly and attacking its own tissues, leading to autoimmune disorders.

This disease is inherited in an autosomal recessive pattern, that is, both copies of the gene in every cell must have mutations for alteration is expressed. The parents of an individual with an autosomal recessive disease have a copy of the mutated gene, but usually show no signs and symptoms of the disease.

Tests in IVAMI: in IVAMI perform detection of mutations associated with deficiency of complement factor I, by complete PCR amplification of exons CFI gene, and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).