Which of the following statements is correct regarding 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. Severe combined immunodeficiency (SCID). SCID is a group of rare genetic disorders that affect both T cells and B cells, resulting in a severe impairment of the immune system. Individuals with SCID are highly susceptible to infections and may need to live in a protected environment to avoid exposure to pathogens, hence the term "bubble boy disease."

Incorrect choices:

a. DiGeorge syndrome is a primary immunodeficiency disorder characterized by abnormalities in the development of certain organs, including the thymus, leading to impaired T cell function, but it does not affect B cell function.

b. X-linked agammaglobulinemia is a primary immunodeficiency disorder characterized by a lack of mature B cells and an inability to produce antibodies, but it does not affect T cell function.

d. Acquired immunodeficiency syndrome (AIDS) is a secondary immunodeficiency disorder caused by the human immunodeficiency virus (HIV) infection, which specifically targets and destroys CD4+ T cells, but it does not affect B cell function.