Which of the following clinical manifestations is often observed in individuals with severe combined immunodeficiency (SCID)?

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 d. Flow cytometry for lymphocyte subsets. Flow cytometry is a diagnostic test used to analyze the quantity and types of lymphocytes in the blood, which helps identify abnormalities in the immune system and diagnose immunodeficiency disorders.

Incorrect choices:

a. A complete blood count (CBC) provides general information about the client's overall blood cell counts, but it does not specifically diagnose immunodeficiency disorders.

b. Urinalysis is used to assess kidney function and identify urinary tract infections but is not a specific test for diagnosing immunodeficiency disorders.

c. Skin testing for allergies is performed to identify allergic reactions to specific allergens and is not used to diagnose immunodeficiency disorders.