3种少见α地中海贫血点突变杂合取合予的临床特征

目的：了解3种少见α地中海贫血点突变血红蛋白Constants Spring （Hb CS），血红蛋白Westmead（Hb WS）和血红蛋白Quong Sze（Hb QS）]杂合子与双重杂合子的临床特征。方法：收集135例上述3种α-地中海贫血点突变的杂合子与双重杂合子患者和正常对照男女各20例，进行血常规参数分析、血红蛋白分析、等位基因特异性寡核苷酸探针反向斑点杂交方法（RDB）和多重跨越断裂点聚合酶链反应（PCR）方法检测基因型。结果：杂合子组、Hb CS和Hb WS双重杂合子（αCSα/αWSα）组均无临床表现，但Hb QS杂合子（αQSα/αα）组的红细胞平均体积（MCV）和红细胞平均血红蛋白（MCH）值小于其余杂合子组（P＜0.05）。Hb CS和Hb QS双重杂合子（αCSα/αQSα）组有轻微的临床表现，MCV和MCH值低于Hb CS杂合子和Hb WS杂合子组（P＜0.05）。结论：Hb CS杂合子组和Hb WS杂合子组表现为静止型地中海贫血，Hb QS杂合子组更接近轻型地中海贫血。双重杂合子表型多样，Hb CS和Hb WS双重杂合子表现接近于静止型地中海贫血，而Hb CS和Hb QS双重杂合子表现类似中间型α地中海贫血（Hb H病），在遗传咨询中需注意。

Clinical Characteristics of Heterozygote and Double Heterozygote of Three Rare Mutations in alphaThalassemia

Objective：To examine clinical characteristics of heterozygote and double heterozygote of three rare mutations Hb Constants Spring（Hb CS）,Hb Westmead（Hb WS） and Hb Quong Sze（Hb QS）] among alpha-thalassemia patients in Guangxi province, China. Methods：135 alpha-thalassemia patients, and 40 controls, were included in this study. Routine examination of blood and hemoglobin electrophoresis were performed. The alpha-thalassemia mutations were detected using Gap-PCR and reverse dot-blotting. Results：There were no clinical symptoms in three heterozygote groups and the double heterozygote group of αCSα/αWSα. MCV and MCH in the heterozygote group of Hb QS were significantly lower than those in other heterozygote groups （Hb CS and Hb WS） （P〈0.05）. However,there was mild clinical symptoms in the double heterozygote group of αCSα/αQSα, while MCV and MCH were also significantly lower than those in other heterozygote groups （Hb CS and Hb WS） （P〈0.05）. Conclusions： The heterozygote Hb CS,heterozygote Hb WS and double heterozygoteαCSα/αWSαare the silent carrier in clinical manifestations, the heterozygote Hb QS is the thalassemia trait, and the double heterozygote αCSα/αQSα is similar to the HbH disease. It is important to note this variability of clinical manifestations of those double heterozygotes in genetic consultation.