Which of the following statements accurately describes 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.

Explanation: The correct answer is c. Common variable immunodeficiency (CVID) is characterized by a deficiency or absence of B cells, leading to a reduced ability to produce antibodies and an increased susceptibility to infections.

Incorrect choices:

a. DiGeorge syndrome is a disorder caused by a genetic defect resulting in the underdevelopment of the thymus and parathyroid glands, leading to T cell deficiency.

b. Severe combined immunodeficiency (SCID) is a severe form of immunodeficiency that affects both B and T cells, leading to a complete absence or dysfunction of the immune system.

d. Wiskott-Aldrich syndrome is a rare X-linked genetic disorder characterized by a triad of symptoms, including eczema, low platelet count, and immunodeficiency. It primarily affects T cells and platelets, not B cells.