In DiGeorge syndrome, the implicated pharyngeal arches are which pair?

In DiGeorge syndrome, the implicated pharyngeal arches are which pair?

• A. First and Second
• B. Second and Third
• C. Third and Fourth
• D. Fourth and Fifth

Answer: (C)

DiGeorge syndrome arises from a disruption in neural crest–derived contributions to the third and fourth pharyngeal pouches during development. These pouches are responsible for forming the thymus (from the third pouch) and the parathyroid glands (inferior from the third pouch and superior from the fourth). When this development is impaired, thymic tissue is reduced, leading to T-cell immunodeficiency, and the parathyroids are underdeveloped, causing hypocalcemia. That combination points to the third and fourth pharyngeal pouches as the implicated pair.

DiGeorge syndrome arises from a disruption in neural crest–derived contributions to the third and fourth pharyngeal pouches during development. These pouches are responsible for forming the thymus (from the third pouch) and the parathyroid glands (inferior from the third pouch and superior from the fourth). When this development is impaired, thymic tissue is reduced, leading to T-cell immunodeficiency, and the parathyroids are underdeveloped, causing hypocalcemia. That combination points to the third and fourth pharyngeal pouches as the implicated pair.