USMLE-Rx Step 1 Qmax Challenge #1278

Check out today’s Step 1 Qmax Question Challenge.

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A 30-year-old woman is found unconscious in her home by her husband. On arrival in the emergency department, she is noted to have thin, translucent skin over her abdomen with prominent varicose veins and many bruises on her shins. He denies any major medical problems in her past, though does report that she always seemed to “bruise really easily.” Her husband thinks the patient’s mother may have had similar problems with bruising, and also that she had “some sort of surgery” when her intestine was found to “have a hole in it.” An autopsy is performed, and an abnormality is discovered in the circle of Willis, similar to that shown in the image.

Which of the following proteins was most likely defective in this patient?

A. Fibrillin-1
B. Keratin 14
C. Type I procollagen
D. Type III procollagen
E. Type IV collagen

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