USMLE® Step 1 style questions USMLE
A 12-year-old girl comes to the pediatrician’s office because of a recently diagnosed streptococcal infection. She has a history of repeated bouts of staphylococcal and streptococcal infections throughout her life, for which she had been prescribed antibiotics each time. Physical examination shows features similar to defective melanin synthesis. Which of the following immune deficiencies is most likely present in this patient?