General Pathology USMLE Step 1 Practice Question
A 47-year-old man presents with a 3-month history of fatigue, early satiety, and 12-lb unintentional weight loss. Vital signs: BP 138/82, HR 102, RR 18, Temp 37.2°C, SpO2 98% on room air. Examination reveals marked splenomegaly; lymph nodes are not palpable. CBC shows WBC 185,000/μL with increased mature granulocytes and basophils. Philadelphia chromosome t(9;22) is identified on cytogenetics. Which pathogenic consequence results from this translocation?
Answer choices
- AOverexpression of an antiapoptotic mitochondrial protein
- BAmplification of a membrane growth factor receptor
- CConstitutive activation of a tyrosine kinaseCorrect answer
- DInactivation of a DNA mismatch repair protein
- ELoss of the G1 to S checkpoint regulator RB
- FIncreased expression of a tumor suppressor gene on chromosome 22
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