A 5 years old child presented with absence of thymus, hypoparathyroidism and tetany. Which of the following marked area is defective in this case?
Answer- C. C
Absence of thymus, hypoparathyroitlism und tetany (suggestive of developmental anomaly of parathyroid) is suggestive of DiGeorge syndrome, which results from dysmorphogenesis of the 3rd and 4th pharyngeal pouches during early embryogenesis, leading to hypoplasia or aplasia of the thymus and parathyroid glands and signs and symptoms hypocalcemia. Thymus develops from 3rd branchial pouch and there is absence of thymus in the patient, out of 3rd and 4th branchial pouch, the better answer is 3rd pouch.