Uncategorized

USMLE-Rx Step 1 Qmax Challenge #1372

Check out today’s Step 1 Qmax Question Challenge.

Know the answer? Post it below! Don’t forget to check back for an update with the correct answer and explanation (we’ll post it in the comments section below).

USMLE-Rx Step 1 Qmax Challenge #1372.pngA 10-year-old boy is brought to the emergency department after falling from his bicycle. He presents with a large, painfully swollen knee; aspiration shows gross hemarthrosis. On further questioning, the patient’s parents say that he bruises easily and that it took several days for the bleeding to completely stop after losing a tooth 1 month ago. His maternal uncle had similar bleeding difficulties. After further testing, the patient is diagnosed with an X-linked recessive disorder.

Which of the following laboratory test results corresponds to the patient’s disorder?

A. A
B. B
C. C
D. D
E. E

———————–

Want to know the ‘bottom line?’ Purchase a USMLE-Rx Subscription and get many more features, more questions, and passages from First Aid, including images, references, and other facts relevant to this question.

This practice question is an actual question from the USMLE-Rx Step 1 test bank. For more USMLE Step 1 prep, subscribe to our Flash Facts and Step 1 Express video series. Score the best deal on all three products with a Step 1 Triple Play Bundle.

Categories: Uncategorized

12 replies »

  1. A)
    Hemophilia with Factor VIII (Antihaemophilic Factor) deficiency which is a component of Intrinsic Pathway of Coagulation which in turn is monitored by aPTT.
    It does not affect platelets, BT and Extrinsic Pathway of Coagulation.

    Like

  2. A, because bleeding time is normal in hemophilia (platelet function is intact), prothrombin time (PT) is normal in hemophilia (because of extrinsic factor, especially FVII, is normal in hemophilia – not in vitamin K deficiency or under warfarin treatment) and partial thromboplastin time (PTT) is extended since PTT involves all clotting factors (so including the ones involved in hemophilia) except FVII and FXIII.

    Like

Leave a Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s