Which of the following is a common clinical manifestation of immunodeficiency disorders?

Explanation: The correct answer is c. Frequent and severe infections. Immunodeficiency disorders impair the body's ability to fight infections, leading to recurrent and severe infections. This is a hallmark sign of immunodeficiency.

Incorrect choices:

a. Hyperactivity and restlessness are not typical clinical manifestations of immunodeficiency disorders. These symptoms are more commonly associated with conditions like attention deficit hyperactivity disorder (ADHD).

b. Increased appetite and weight gain are not specific to immunodeficiency disorders. They may be seen in conditions like hypothyroidism or certain eating disorders.

d. Hypertension and tachycardia are not characteristic clinical manifestations of immunodeficiency disorders. These symptoms may be associated with cardiovascular issues.

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.