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 b. X-linked agammaglobulinemia. X-linked agammaglobulinemia is a primary immunodeficiency disorder caused by a genetic mutation that leads to the absence of mature B cells, resulting in an inability to produce antibodies (immunoglobulins). As a result, individuals with this disorder are highly susceptible to infections, especially bacterial infections.

Incorrect choices:

a. DiGeorge syndrome is a primary immunodeficiency disorder characterized by abnormalities in the development of certain organs, including the thymus, leading to impaired T cell function.

c. Severe combined immunodeficiency (SCID) is a group of rare genetic disorders that affect both T cells and B cells, resulting in a severe impairment of the immune system.

d. Acquired immunodeficiency syndrome (AIDS) is a secondary immunodeficiency disorder caused by the human immunodeficiency virus (HIV) infection, which specifically targets and destroys CD4+ T cells, weakening the immune system's ability to fight infections.

Explanation: The correct answer is c. Severe combined immunodeficiency (SCID). SCID is a group of rare genetic disorders that affect both T cells and B cells, resulting in a severe impairment of the immune system. Individuals with SCID are highly susceptible to infections and may need to live in a protected environment to avoid exposure to pathogens, hence the term "bubble boy disease."

Incorrect choices:

a. DiGeorge syndrome is a primary immunodeficiency disorder characterized by abnormalities in the development of certain organs, including the thymus, leading to impaired T cell function, but it does not affect B cell function.

b. X-linked agammaglobulinemia is a primary immunodeficiency disorder characterized by a lack of mature B cells and an inability to produce antibodies, but it does not affect T cell function.

d. Acquired immunodeficiency syndrome (AIDS) is a secondary immunodeficiency disorder caused by the human immunodeficiency virus (HIV) infection, which specifically targets and destroys CD4+ T cells, but it does not affect B cell function.