The nurse is caring for a child with severe combined immunodeficiency (SCID). Which precaution should the nurse take to protect the child from infections?

Explanation: The correct answer is c. Common variable immunodeficiency (CVID) is characterized by a deficiency or absence of B cells, leading to a reduced ability to produce antibodies and an increased susceptibility to infections.

Incorrect choices:

a. DiGeorge syndrome is a disorder caused by a genetic defect resulting in the underdevelopment of the thymus and parathyroid glands, leading to T cell deficiency.

b. Severe combined immunodeficiency (SCID) is a severe form of immunodeficiency that affects both B and T cells, leading to a complete absence or dysfunction of the immune system.

d. Wiskott-Aldrich syndrome is a rare X-linked genetic disorder characterized by a triad of symptoms, including eczema, low platelet count, and immunodeficiency. It primarily affects T cells and platelets, not B cells.

The correct answer is c. Ataxia-telangiectasia. Ataxia-telangiectasia is a rare genetic disorder that affects the cerebellum, causing poor muscle coordination (ataxia) and small, dilated blood vessels (telangiectasias). It also leads to defective T-cell function, making affected individuals more susceptible to infections.

Incorrect choices:

a. X-linked agammaglobulinemia (XLA) is a primary immunodeficiency disorder that primarily affects B-cell function, leading to a lack of mature B cells and low levels of immunoglobulins, but does not involve defective T-cell function.

b. Selective immunoglobulin A (IgA) deficiency is characterized by a deficiency of IgA, but it does not typically lead to defective T-cell function.

d. DiGeorge syndrome is caused by a deletion on chromosome 22 and primarily affects the development of certain organs, including the thymus and parathyroid glands, resulting in T-cell deficiency. While it may lead to some B-cell abnormalities, defective T-cell function is the hallmark of this disorder.