成人健檢時發現血小板高達1500×10⁹/L，腹部超音波顯示脾臟腫大。醫師懷疑是真性血小板增多症（essential thrombocythemia），下列何種基因異常較不常見？
AJAK2 (Janus-associated kinase 2) gene mutation
BMPL (thrombopoietin receptor) gene mutation
CPDGFRA (platelet-derived growth factor receptor A) gene mutation正確答案
DCALR (calreticulin) gene mutation
答案與詳解
