HMP Shunt

(M1.BC.17.4707) A 12-year-old boy presents to the emergency department with fatigue and back pain. He has also had tea-colored urine over the last 24 hours. Upon being asked about changes to his routine over the last week, he remembers running a 5K, trying alcohol with a friend, and having a large meal at a friend's house with ingredients that he did not recognize. On physical exam he appears to be pale with conjunctival pallor. Labs are as follows:

Hemoglobin: 11 g/dL
Hematocrit: 32%
Mean Corpuscular Volume: 88 fL

Peripheral blood smear findings are shown in Figure A. An enzyme defect in which of the following pathways is likely responsible for this patient's symptoms?

(M1.BC.15.74) A 32-year-old male with HIV presents to his physician with complaints of shortness of breath and fatigue. He has a history of being non-compliant with his HAART regimen, and his CD4 count is found to be 149. The physician obtains a chest radiograph, which is shown in Figure A. Further workup demonstrates that the patient is infected with the organism demonstrated in Figure B. The physician prescribes the first-line treatment for this infection. One day later, the patient returns complaining of severe weakness and dark colored urine. On exam, the physician notes that the patient is jaundiced, and a peripheral blood smear demonstrates the findings shown in Figure C. Which of the following would most mimic this patient's condition?

(M1.BC.13.22) A 55-year-old African American lawyer presents to your office with complaints of fatigue, back pain and dark urine that he notices in the morning when he wakes up. The patient is well known to you. He frequently travels to Bangkok where he has admitted to having unprotected sex. You have treated him in the past for chlamydia, gonorrhea and syphilis. This patient has a family history of sickle cell disease in 4 of his brothers. He has a past medical history of HIV and his most recent CD4 count was 147 cells/µL. His current medications include lisinopril, glyburide, metformin, ibuprofen, and buspirone. Appropriate prophylactic measures were taken one week ago account for his low CD4 count and his traveling. The patient's CBC demonstrates:

Hemoglobin: 9 g/dL
Hematocrit: 32%
White blood cell count: 3,600 cells/µL
Platelets: 155,000/µL

A peripheral blood smear is shown in Figure A. A chest radiograph is shown in Figure B.

Which of the following is the best explanation for this patient's symptoms?