3歲男孩,斷母乳后一直飲鮮牛奶(喜冷飲),常有餐后臍周陣痛,面色蒼白3個(gè)月,肝肋下可觸及,脾未及,RBC4.0×10/L,Hb90g/L,MCV72fl,網(wǎng)織紅細(xì)胞0.015,WBC和PLT正常。外周血涂片示紅細(xì)胞大小不等,以小細(xì)胞為主,中央淺染并可見多嗜性紅細(xì)胞(見圖)。血清鐵蛋白11.2μmol/L,紅細(xì)胞游離原卟啉1.2μmol/L,最可能的診斷是()