PDF(Pubmed)
Abstract：
Thalassemic diseases are characterized by a reduced (β+) or absent (β0) synthesis of the globin chains of hemoglobin (Hb) due to genetic mutations. β-thalassemia was more frequent in the Mediterranean area, but now it is diffused worldwide. Three possible genetic forms can be distinguished: β0/β0, the most severe (Cooley\'s disease); β0/β+ of intermediate severity; β+/β+ associated with β-thalassemia intermedia or minor. Recently, a clinical non-genetic classification has been proposed: transfusion-dependent thalassemia (TDT), requiring regular lifetime blood transfusions, and non-transfusion-dependent thalassemia (NTDT), requiring occasional transfusions to manage acute cases. In this report, we studied a patient whose blood count indicated a severe anemia but also showed thrombocytosis, leukocytosis, and an elevated number of nucleated red blood cells (NRBC). These altered blood parameters suggested initially a possible diagnosis of hemoglobinopathy or myeloproliferative syndrome. The molecular and genetic analyses demonstrated the presence of HbF (5.3%) and HbA2 (7.7%) and the presence of the homozygote mutation (IVS1.6T>C) in the β-globin gene. According to these data, a diagnosis of β-thalassemia intermedia form has been proposed. Nevertheless, the clinical condition, the presence of thrombocytosis, leukocytosis, an elevated number of NRBC, and the frequent blood transfusions lead to reclassification of the patient as TDT subject. Consequently, this result suggests that a unique genotype-phenotype correlation is not possible in the presence of β+mutations since other concomitant pathologies can exacerbate the disease.
摘要：
地中海贫血疾病的特征在于由于遗传突变导致的血红蛋白(Hb)的珠蛋白链的合成减少(β+)或缺失(β0)。β-地中海贫血在地中海地区更为常见，但现在它在世界范围内传播。可以区分三种可能的遗传形式：β0/β0，最严重（Cooley病）；中度严重程度的β0/β；β/β与中间或轻度β-地中海贫血相关。最近,已经提出了临床非遗传分类：输血依赖性地中海贫血（TDT），需要定期输血，和非输血依赖性地中海贫血（NTDT），需要偶尔输血来处理急性病例。在这份报告中,我们研究了一名患者，其血细胞计数显示严重贫血，但也显示血小板增多症，白细胞增多,和有核红细胞（NRBC）数量增加。这些改变的血液参数最初表明可能诊断为血红蛋白病或骨髓增生综合征。分子和遗传分析表明在β-珠蛋白基因中存在HbF(5.3%)和HbA2(7.7%)和纯合子突变(IVS1.6T>C)。根据这些数据,已经提出了中间型β-地中海贫血的诊断。然而，临床状况，血小板增多症的存在,白细胞增多,NRBC的数量增加,频繁的输血导致患者重新分类为TDT受试者。因此,这一结果表明,在存在β+突变的情况下,独特的基因型-表型相关性是不可能的,因为其他伴随的病理可以加重疾病.
