Bare Lymphocyte Syndrome 2

SCID due to absent class II HLA antigens

Overview

Type of disease: Rare conditions

Bare Lymphocyte Syndrome (BLS) type 2 is a variation of bare lymphocyte syndrome and affects the immune system. The immune system works to defend our bodies from infection. Two important cells in our immune system are the T cells and the B cells. They work together to kill viruses and bacteria that enter our bodies. BLS type 2 makes our bodies unable to produce T cells. It also affects the ability of immune system cells to make antibodies. These antibodies are used to recognize and remember infections we have had so individuals don’t get infected again. Those affected by this disorder do not develop like they should and get serious infections that often do not respond to medications. The disorder increases susceptibility to viral, bacterial, and fungal infections and individuals also have chronic diarrhea. This condition is often fatal in childhood.

BLS type 2, is a genetic condition caused by a change (mutation) in the MHC2TA, RFX5, RFXAP, and RFXANK genes. BLS type 2 is passed down from parent to child in an autosomal recessive manner, which means one mutation from each parent is needed to cause symptoms. A person with only one mutation is called a carrier because they “carry” one changed copy and one unchanged copy of the gene. Carriers also show no signs or symptoms of the condition. If both parents are carriers, each of their children has a one in four chance (25%) of having the condition and a 50/50 chance of being a carrier.

Treatment depends on the type of infection that develops. If you or a family member has been diagnosed with BLS type 2, talk with your doctor about the most current treatment options. Support groups are also good resources for support and information.

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