The nurse is caring for an infant suspected of having severe combined immunodeficiency (SCID). Which diagnostic test should the nurse anticipate being prescribed for the infant?

Explanation: The correct answer is b. Common variable immunodeficiency (CVID). CVID is a primary immunodeficiency disorder characterized by a reduced level of immunoglobulins, particularly IgA, leading to an increased susceptibility to infections.

Incorrect choices:

a. Severe combined immunodeficiency (SCID) is a more severe immunodeficiency disorder that affects multiple components of the immune system, not specifically IgA levels.

c. DiGeorge syndrome is caused by a genetic abnormality and is characterized by a defect in the development of certain organs, including the thymus and parathyroid glands. It may result in immune system abnormalities but does not primarily involve IgA deficiency.

d. Wiskott-Aldrich syndrome is a rare X-linked genetic disorder that affects platelet function and immune system regulation but is not specifically associated with IgA deficiency.

Explanation: The correct answer is c. X-linked agammaglobulinemia. This disorder primarily affects males and is caused by mutations in the BTK gene, resulting in a lack of mature B cells and immunoglobulins.

Incorrect choices:

a. Selective IgA deficiency is a primary immunodeficiency disorder characterized by a deficiency of immunoglobulin A (IgA), and it can affect both males and females.

b. DiGeorge syndrome is caused by a chromosome 22 deletion and is not inherited in an X-linked recessive pattern.

d. Severe combined immunodeficiency (SCID) is a group of disorders that can be inherited in various patterns, including autosomal recessive, autosomal dominant, or X-linked recessive. SCID affects both males and females and results in a severe deficiency of T cells, B cells, and natural killer (NK) cells.