Which of the following clinical manifestations is commonly seen in individuals with immunodeficiency disorders?

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.

Explanation: The correct answer is c. Serum immunoglobulin levels. A primary immunodeficiency disorder often results in abnormal levels of immunoglobulins (antibodies) in the blood. Measuring serum immunoglobulin levels can help identify potential deficiencies and guide the diagnosis of primary immunodeficiency disorders.

Incorrect choices:

a. Enzyme-linked immunosorbent assay (ELISA) is a test used to detect specific antibodies or antigens in the blood, but it is not specific to diagnosing primary immunodeficiency disorders.

b. A chest X-ray is not a specific test for diagnosing primary immunodeficiency disorders. It is typically used to assess the condition of the lungs and chest organs.

d. A complete blood count (CBC) is a general blood test that may reveal abnormalities in white blood cell count but does not specifically assess immunoglobulin levels.