A 2 month old boy has recurrent viral and fungal infections, difficulty feeding, and episodes of perioral twitching. He was born with a conotruncal cardiac defect. Physical examination shows low set ears and a small jaw. Laboratory studies reveal hypocalcemia and decreased T cell count. Which embryologic structure most likely failed to develop properly?
- A)Dorsal pancreatic bud
- B)Third and fourth pharyngeal pouchesGABARITO
- C)First pharyngeal arch
- D)Neural crest migration into the aorticopulmonary septum only
- E)Second pharyngeal arch
Explicação
This infant has DiGeorge syndrome due to abnormal development of the third and fourth pharyngeal pouches, leading to thymic and parathyroid aplasia. The recurrent viral and fungal infections reflect T cell deficiency, while hypocalcemia and conotruncal abnorma... Ver explicação completa e trilha adaptativa →