Which of the following clinical manifestations is a common symptom of primary immunodeficiency disorders?

Explanation: The correct answer is c. Failure to thrive. SCID is a severe form of immunodeficiency that affects multiple components of the immune system, leading to recurrent and severe infections and failure to thrive in affected infants.

Incorrect choices:

a. Recurrent ear infections are more commonly seen in other types of immunodeficiency disorders, such as selective IgA deficiency.

b. Chronic fatigue and lethargy may be seen in various medical conditions but are not specific to SCID.

d. Persistent joint pain is not a characteristic symptom of SCID. It may be associated with other autoimmune or inflammatory conditions.

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.