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T-cell related lymphocyte deficiencies

(T-Cell • related • lim-fuh-site • di-FISH-uhn-seez)

General Condition Information

Other Names

  • Non-SCID primary immunodeficiencies or other conditions associated with low T-cells
  • T-cell lymphopenia
  • T-cell lymphopenias

Condition Type

Birth Prevalence

  • It is estimated that approximately 1000 babies are born with the most common form of this condition, 22q11.2 deletion syndrome, each year in the United States.
  • It is estimated that fewer than 100 babies are born with another form of this condition, ataxia-telangiectasia, each year in the United States.

Screening Finding

Decreased T cell receptor excision circles (TRECs)

What is t-cell related lymphocyte deficiencies

T-cell related lymphocyte deficiencies are a group of inherited (genetic) conditions where a baby is born with a decreased immune system. 

The immune system fights infections. The immune system uses special white blood cells called lymphocytes to fight against germs that invade the body. Lymphocytes include T cells, B cells, and natural killer (NK) cells.

Babies with T-cell related lymphocyte deficiencies, either do not have T cells, have a decreased number of T cells, or have T cells that do not work normally. There are several types of T-cell related lymphocyte deficiencies, including 22q11.2 deletion syndrome and ataxia-telangiectasia. All types have low and/or abnormal T-cells but the different types may affect different parts of the body. When the cause of the T-cell deficiency is unknown, the condition is called idiopathic T-cell lymphopenia.

If the immune system is weak, your baby’s body has trouble fighting infections. They can get sick from germs that do not infect people with working immune systems, leading to the signs and symptoms of the condition. Without treatment and special protection from germs, T-cell related lymphocyte deficiencies can lead to life-threatening illness or death.

Newborn Screening and Follow-Up

Condition Details

Treatment and Management

It is important to talk to your health care provider about which treatment(s) are best for your baby. The goal of treatment is to prevent the health problems caused by this condition. 

Treatments may include the following:

Children who receive early and ongoing treatment for T-cell lymphocyte deficiency are less likely to have life-threatening infections and illnesses. Children who receive bone marrow or thymus transplants can lead healthy lives.

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