USMLE® Step 1 style questions USMLE
USMLE® Step 2 style questions USMLE
A 20-year-old man comes to the clinic because of a raspy voice for the past two weeks. He plays quarterback for a college football team and has been unable to yell out plays to his teammates due to the hoarseness. His medical history is noncontributory and he does not take any medications. He denies recent flu symptoms or sick contacts. He has occasional chest pain that radiates to his neck. Family history is significant for a maternal uncle who died of a "heart condition" at 31-years-old. His temperature is 37.0°C (98.6°F), pulse is 68/min, respirations are 14/min, and blood pressure is 138/69 mm Hg. Physical examination shows a tall slender male with pectus excavatum, and a 3/6 systolic murmur with a mid-systolic click is heard at the apex on auscultation of the chest. Which of the following proteins is most likely defective in this patient?