C4 deficiency is a rare genetic disorder resulting from a mutation in the C4 gene, which is responsible for producing the C4 protein. The C4 protein functions as part of the complement system, which is an innate immune system component that helps to protect the body from infections. Without the C4 protein, the body’s ability to fight infections is significantly reduced, leading to chronic, recurrent, and often severe infections.
The most common type of C4 deficiency is referred to as C4A deficiency, which is caused by a mutation in the gene responsible for C4A production. In addition, another form of C4 deficiency, C4B deficiency, can also occur due to a mutation in the gene responsible for C4B production. Both C4A and C4B deficiencies can result in recurrent infections, as well as a wide range of other symptoms, including fatigue, joint and muscle pain, and an increased susceptibility to certain autoimmune diseases.
Treatment for C4 deficiency is typically focused on managing the symptoms and preventing infections. This may include the use of antibiotics, immunosuppressants, and immune globulin infusions. In addition, researchers are currently exploring gene therapy as a potential treatment for C4 deficiency.