Primary Immunodeficiency (PI) is an umbrella term for over 350 genetic defects and disorders of the immune system recognized by the World Health Organization. Together they affect approximately 29,000 Canadians. Primary Immunodeficiency is not considered a rare disease as a category, but each individual form of PI is rare.
There are currently 3 names in this directory beginning with the letter T.
TLR Deficiencies
Toll-like Receptors (TLRs) are proteins that send internal messages to the white blood cell to secrete cytokines, which stimulate the immune system. When the TLRs are defective, innate immune cells cannot kill invading microbes, leading to recurring infections. There are various disorders that are occur because of TLR Deficiency, such as MyD88 deficiency and IRAK-4 deficiency. Having the TLR Deficiency will result in a susceptibility to infections from bacteria and viruses.
Credits: Immune Deficiency Foundation
Transcobalamin II Deficiency
Transcobalamin II Deficiency is a hereditary condition that impairs the transport of vitamin B12 within the body. The symptoms of the condition are anemia, low white cell count, and hypogammaglobulinemia. The condition also results in a failure to thrive (grow or gain weight). Transobalamin II Deficiency can be treated with B12 injections. The estimated frequency of the condition is unknown.
Credits: Immune Deficiency Foundation, Genetics Home Reference
Transient Hypogammaglobulinemia of Infancy
THI is a condition diagnosed in infants over the age of 6 months who have significantly lower levels of IgG (antibody) than normal. The condition is not permanent and many infants are asymptomatic. However, lowered IgG levels could present a susceptibility to respiratory infections, allergic manifestations, gastrointestinal issues, ear/sinus infections, nasal/throat infections, and swollen glands. The infections should be treated with antibiotics and live viral vaccines should be avoided until the IgG levels improve. Individuals with THI typically develop regular levels of IgG by the age of 3.
The condition is twice as likely to occur in males. The estimated frequency of the condition is unknown, but it is believed to be underdiagnosed.
Credits: Immune Deficiency Foundation