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Bare lymphocyte syndrome type 2, complementation group A

MedGen UID:
395288
Concept ID:
C1859534
Disease or Syndrome
Synonym: Bare Lymphocyte Syndrome, Type II, Complementation Group A
 
OMIM®: 209920; 600005

Definition

Bare lymphocyte syndrome type II (BLS II) is an inherited disorder of the immune system categorized as a form of combined immunodeficiency (CID). People with BLS II lack virtually all immune protection from bacteria, viruses, and fungi. They are prone to repeated and persistent infections that can be very serious or life-threatening. These infections are often caused by "opportunistic" organisms that ordinarily do not cause illness in people with a normal immune system.

In people with BLS II, infection-fighting white blood cells (lymphocytes) are missing specialized proteins on their surface called major histocompatibility complex (MHC) class II proteins, which is where the condition got its name. Because BLS II is the most common and best studied form of a group of related conditions, it is often referred to as simply bare lymphocyte syndrome (BLS).

BLS II is typically diagnosed in the first year of life. Most affected infants have persistent infections in the respiratory, gastrointestinal, and urinary tracts. Because of the infections, affected infants have difficulty absorbing nutrients (malabsorption), and they grow more slowly than their peers. Eventually, the persistent infections lead to organ failure. Without treatment, individuals with BLS II usually do not survive past early childhood. [from MedlinePlus Genetics]

Clinical features

From HPO
Recurrent urinary tract infections
MedGen UID:
120466
Concept ID:
C0262655
Disease or Syndrome
Repeated infections of the urinary tract.
Failure to thrive
MedGen UID:
746019
Concept ID:
C2315100
Disease or Syndrome
Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.
Colitis
MedGen UID:
40385
Concept ID:
C0009319
Disease or Syndrome
Ulcerative colitis is a chronic disorder that affects the digestive system. This condition is characterized by abnormal inflammation of the inner surface (epithelium) of the rectum and colon. The rectum and colon make up most of the length of the large intestine. The inflammation usually causes open sores (ulcers) to develop in the large intestine. Ulcerative colitis usually appears between the age of 15 and 30, although it can develop at any age. The inflammation tends to flare up multiple times throughout a person's life, which causes recurring signs and symptoms.\n\nThe most common symptoms of ulcerative colitis are cramping abdominal pain and frequent diarrhea, often with blood, pus, or mucus in the stool. Other signs and symptoms include nausea, loss of appetite, bowel urgency, fatigue, and fevers. Chronic bleeding from the inflamed and ulcerated intestinal tissue can cause a shortage of red blood cells (anemia) in some affected individuals. People with this disorder have difficulty absorbing enough fluids and nutrients from their diet and often experience weight loss. Affected children usually grow more slowly than normal. Less commonly, ulcerative colitis causes problems with the skin, joints, eyes, kidneys, or liver, which are most likely due to abnormal inflammation.\n\nToxic megacolon is a rare complication of ulcerative colitis that can be life-threatening. Toxic megacolon involves a widening (dilation) of the colon and an overwhelming inflammatory response. Ulcerative colitis also increases the risk of developing colon cancer, especially in people whose entire colon is inflamed and in those who have had ulcerative colitis for 8 years or more.\n\nUlcerative colitis is one common form of inflammatory bowel disease (IBD). Another type of IBD, Crohn's disease, also causes chronic inflammation of the intestines. Unlike ulcerative colitis, which affects only the inner surface of the large intestine, Crohn's disease can cause inflammation in any part of the digestive system, and the inflammation extends deeper into the intestinal tissue.
Viral hepatitis
MedGen UID:
22652
Concept ID:
C0042721
Disease or Syndrome
Inflammation of the liver due to infection with a virus.
Protracted diarrhea
MedGen UID:
141631
Concept ID:
C0473133
Disease or Syndrome
Biliary tract abnormality
MedGen UID:
108201
Concept ID:
C0549613
Finding
An abnormality of the biliary tree.
Villous atrophy
MedGen UID:
154306
Concept ID:
C0554101
Finding
The enteric villi are atrophic or absent.
Malabsorption
MedGen UID:
811453
Concept ID:
C3714745
Finding
Impaired ability to absorb one or more nutrients from the intestine.
Recurrent upper respiratory tract infections
MedGen UID:
154380
Concept ID:
C0581381
Disease or Syndrome
An increased susceptibility to upper respiratory tract infections as manifested by a history of recurrent upper respiratory tract infections (running ears - otitis, sinusitis, pharyngitis, tonsillitis).
Recurrent lower respiratory tract infections
MedGen UID:
756211
Concept ID:
C3163798
Disease or Syndrome
An increased susceptibility to lower respiratory tract infections as manifested by a history of recurrent lower respiratory tract infections.
Agammaglobulinemia
MedGen UID:
168
Concept ID:
C0001768
Disease or Syndrome
A lasting absence of total IgG and total IgA and total IgM in the blood circulation, whereby at most trace quantities can be measured.
Chronic mucocutaneous candidiasis
MedGen UID:
2426
Concept ID:
C0006845
Disease or Syndrome
Recurrent or persistent superficial Candida infections of the skin, mucous membranes, and nails.
Cholangitis
MedGen UID:
40258
Concept ID:
C0008311
Disease or Syndrome
Inflammation of the biliary ductal system, affecting the intrahepatic or extrahepatic portions, or both.
Chronic lymphocytic meningitis
MedGen UID:
140725
Concept ID:
C0393441
Disease or Syndrome
Meningitis that persists for more than 4 weeks, and lymphocytes are present in the cerebrospinal fluid (CSF).
Infectious encephalitis
MedGen UID:
108917
Concept ID:
C0596773
Disease or Syndrome
A disorder of the brain caused by an infectious agent that presents with fever, headache, and an altered level of consciousness. There may also be focal or multifocal neurologic deficits, and focal or generalized seizure activity.
Neutropenia
MedGen UID:
163121
Concept ID:
C0853697
Finding
An abnormally low number of neutrophils in the peripheral blood.
Panhypogammaglobulinemia
MedGen UID:
233072
Concept ID:
C1328587
Finding
A reduction in the circulating levels of all the major classes of immunoglobulin. is characterized by profound decreases in all classes of immunoglobulin with an absence of circulating B lymphocytes.
Recurrent viral infections
MedGen UID:
332357
Concept ID:
C1837066
Finding
Increased susceptibility to viral infections, as manifested by recurrent episodes of viral infection.
Recurrent bacterial infections
MedGen UID:
334943
Concept ID:
C1844383
Finding
Increased susceptibility to bacterial infections, as manifested by recurrent episodes of bacterial infection.
Recurrent fungal infections
MedGen UID:
336166
Concept ID:
C1844384
Disease or Syndrome
Increased susceptibility to fungal infections, as manifested by multiple episodes of fungal infection.
Cutaneous anergy
MedGen UID:
344575
Concept ID:
C1855781
Finding
Inability to react to a delayed hypersensitivity skin test.
Recurrent protozoan infections
MedGen UID:
870746
Concept ID:
C4025202
Finding
Increased susceptibility to protozoan infections, as manifested by recurrent episodes of protozoan infection.

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