Which of the following is a potential complication of primary immunodeficiency disorders?

The correct answer is c. Ataxia-telangiectasia. Ataxia-telangiectasia is a rare genetic disorder that affects the cerebellum, causing poor muscle coordination (ataxia) and small, dilated blood vessels (telangiectasias). It also leads to defective T-cell function, making affected individuals more susceptible to infections.

Incorrect choices:

a. X-linked agammaglobulinemia (XLA) is a primary immunodeficiency disorder that primarily affects B-cell function, leading to a lack of mature B cells and low levels of immunoglobulins, but does not involve defective T-cell function.

b. Selective immunoglobulin A (IgA) deficiency is characterized by a deficiency of IgA, but it does not typically lead to defective T-cell function.

d. DiGeorge syndrome is caused by a deletion on chromosome 22 and primarily affects the development of certain organs, including the thymus and parathyroid glands, resulting in T-cell deficiency. While it may lead to some B-cell abnormalities, defective T-cell function is the hallmark of this disorder.

Explanation: The correct answer is d. Immunodeficiency disorders can be caused by medications or medical treatments. Immunodeficiency disorders are conditions in which the immune system is weakened or dysfunctional, leading to an increased susceptibility to infections. They can be primary (genetic) or secondary (acquired). Secondary immunodeficiency disorders can be caused by various factors, including medications (e.g., immunosuppressive drugs used after organ transplants), medical treatments (e.g., chemotherapy for cancer), and certain diseases (e.g., HIV/AIDS).

Incorrect choices:

a. Immunodeficiency disorders are characterized by a weakened immune system, not an overactive one. Overactive immune responses are seen in autoimmune disorders.

b. Immunodeficiency disorders can be both primary (genetic) and secondary (acquired) in nature. While some immunodeficiencies are genetic, others can be acquired later in life due to various factors.

c. Immunodeficiency disorders result in a decreased ability to fight infections, not an increased one. Individuals with immunodeficiencies are more susceptible to infections and may experience recurrent or severe infections.