A 3-month-old infant is rushed to the emergency department in respiratory distress.

Subject
Paediatrics
System
Allergy & Immunology, Pulmonary & Critical Care

Kathryn

Member
Jul 29, 2020
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Singapore
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A 3-month-old infant is rushed to the emergency department in respiratory distress. Her mother notes that she is “always sick.” She has had multiple hospitalizations over the past months, including one for a severe bout of pneumonia with Pneumocystis jiroveci (formerly carinii) and another for respiratory syncytial virus. On admission, she is noted to be below the 5th percentile for weight and length and appears pale and lethargic. Her vital signs include a pulse of 150/min, respirations of 20/min, and a temperature of 38.9° C (102° F). Her mouth is coated with whitish bumps that scrape off easily. This patient is most likely to have a deficiency of which of the following enzymes?
(A) Adenosine deaminase
(B) Aldolase B
(C) Arylsulfatase A
(D) B-cell tyrosine kinase
(E) HGPRTase