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 4 names in this directory beginning with the letter X.
X-Linked Agammaglobulinemia
X-Linked Agammaglobulinemia (XLA), also called Bruton’s Agammaglobulinemia or Congenital Agammaglobulinemia, was first identified in 1952 by Dr. Ogden Bruton. Individuals with X-LA cannot produce antibodies. X-LA is found in approximately 1 in 200,000 newborns; the newborns with the condition are almost exclusively male.
Due to the lack of antibodies, individuals with X-LA are prone to infections, especially of the middle ear (otitis), sinuses (sinusitis), and lungs (pneumonia, bronchitis). Individuals with XLA can also experience gastrointestinal infections, skin infections, and possibly infections that can involve the bloodstream or internal organs.
There is no way to cure individuals who have agammaglobulinemia. They can be treated through intravenous or subcutaneous immunoglobulin transfusion. The immunoglobulin will supply them with more antibodies, and help them fight off infections.
Credits: Immune Deficiency Foundation, Genetics Home Reference
X-linked Immune Dysregulation with Polyendocrinopathy (IPEX)
Individuals with IPEX have multiple autoimmune endocrine (hormone-related) conditions, such as diabetes and thyroid problems. IPEX also results in autoimmune conditions related to the intestines and the skin, resulting in chronic diarrhea, failure to gain weight, rashes and skin irritation.
IPEX is an X-linked disease, so only males are affected. The condition is rare and the estimated percentage of individuals born with IPEX is unknown. It can be treated with immunosuppressive medications and a bone-marrow transplant.
Credits: Immune Deficiency Foundation, Genetics Home Reference
X-Linked Lymphoproliferative Syndrome
X-linked lymphoproliferative disease (XLP) is a disorder of the immune system and blood-forming cells that is found almost exclusively in males. More than half of individuals with this disorder experience an exaggerated immune response to the Epstein-Barr virus (EBV). EBV is a very common virus that eventually infects most humans. In some people it causes infectious mononucleosis (commonly known as "mono"). Normally, after initial infection, EBV remains in certain immune system cells (lymphocytes) called B cells. However, the virus is generally inactive (latent) because it is controlled by other lymphocytes called T cells that specifically target EBV-infected B cells. Recognized by IPOPI . Credits: Immune Deficiency Foundation, Genetics Home Reference
X-SCID
X-SCID is the most common form of Severe Combined Immunodeficiency, the most serious case of primary immunodeficiency. X-SCID affects approximately 45% of all cases. The condition is an X-linked recessive trait, meaning that it primarily affects males.
SCID is a potentially fatal condition that results in high susceptibility to severe, recurrent infection during infancy. Early intervention is ideal for individuals with SCID; placing SCID within newborn screening programs can aid with early diagnosis and treatment. Live virus vaccines should not be given to infants with SCID. Undergoing a bone marrow transplant or gene-therapy could cure the condition.
The exact frequency of the condition is unknown. It is estimated to affect 1 in 50,000 –100,000 newborns.
Credits: Immune Deficiency Foundation, Genetics Home Reference