云南省100例异常血红蛋白E患者的血液学和基因型分析

目的分析云南省异常血红蛋白E(hemoglobin E,Hb E)杂合子及Hb E合并地中海贫血(简称地贫)病例的血液学表型和基因型特征。方法对100例高效液相色谱分析提示为Hb E异常血红蛋白携带病例进行血细胞分析,并用Gap-PCR和PCR-寡核苷酸探针反向斑点杂交法检测α-和β-珠蛋白基因常见突变类型。结果100例疑似Hb E携带的病例,经基因诊断全部检出β-珠蛋白链CD26突变(HBB:c.79G>A),其中Hb E杂合子90例,Hb E合并αα/-α3.7突变7例,Hb E合并αα/--SEA突变2例,1例为Hb E合并-α3.7/-α3.7。Hb E杂合子血液学表型分析结果:Hb A2(26.02±3.64)%,Hb F(1.35±1.25)%,平均红细胞体积(78.83±4.68)fl,平均红细胞血红蛋白含量(26±1.54)pg,平均血红蛋白浓度(329.65±10.73)g/L,血红蛋白(141.08±16.53)g/L;Hb E复合α地贫时,α地贫基因的突变类型不同,血液学表型结果不同。结论云南省Hb E及Hb E合并α地贫的发生率较高,高效液相色谱能够有效检出Hb E,Hb E合并其它α地贫基因突变时,有较大差异的表型变化;仅依靠血液学结果进行产前筛查会造成Hb E漏诊。

Hematological and genotypic features of 100 patients with hemoglobin E disorders from Yunnan Province

Objective To explore hematological and genotypic characteristics of patients with hemoglobin E(Hb E)disorders from Yunnan Province.Methods One hundred individuals with Hb E disorders indicated by high performance liquid chromatography(HPLC)were subjected to genetic testing through multiple gap-PCR and reverse dot-blotting analysis.Results All patients were found to harbor a mutation to the 26th codon of theβ-globin chain(HBB:c.79G>A).Ninety patients were heterozygotes,and 10 co-inherited c.79G>A and anα-thalassemia mutation(7αα/-α3.7,2αα/--SEA and 1-α3.7/-α3.7).Hematological characteristics of the heterozygotes were:Hb A2(26.02±3.64)%,Hb F(1.35±1.25)%,MCV(78.83±4.68)fl,MCH(26±1.54)pg,MCHC(329.65±10.73)g/L,HGB(141.08±16.53)g/L,while that of the co-inherited cases was decided by the type ofα-thalassemia mutation.Conclusion Hb E can be effectively detected by HPLC.The type ofα-thalassemia mutations will determine hematological features of co-inherited cases.Hb E disorders may be missed by relying only on routine blood test upon prenatal screening.