Which of the following immunodeficiency disorders is characterized by a deficiency of immunoglobulin A (Ig

Explanation: The correct answer is d. Abdominal pain and diarrhea. Abdominal pain and diarrhea are common clinical manifestations of immunodeficiency disorders. The weakened immune system makes the child more susceptible to gastrointestinal infections, leading to these symptoms.

Incorrect choices:

a. Rash and hives are more common clinical manifestations of allergic reactions or immune hypersensitivity disorders, not immunodeficiency disorders.

b. Rapid weight loss may be seen in conditions like malnutrition or metabolic disorders but is not a typical clinical manifestation of immunodeficiency disorders.

c. Excessive thirst and frequent urination are clinical manifestations of diabetes or other endocrine disorders, not immunodeficiency disorders.

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.