异常血红蛋白Hb Q-Thailand复合HbH病的分子诊断和产前诊断

Molecular and prenatal diagnosis of hemoglobin H disease combining hemoglobin Q-Thailand

目的通过病例分析探讨产前诊断中检测出Hb H病和异常血红蛋白Q后对α珠蛋白基因进行DNA测序分析的意义。方法采集4个家系成员的外周血标本进行血红蛋白毛细管电泳和红细胞参数的分析,应用gap-PCR、PCR-RDB和DNA测序方法对外周血和产前标本进行α珠蛋白基因的鉴定。结果 4例产前诊断的胎儿标本均检测到4.2缺失型Hb H病复合异常血红蛋白Q-Thailand突变,基因型为--SEA/-α4.2合并HBA1 CD74 G>C。异常血红蛋白Q-Thailand均遗传于母亲。结论α地中海贫血的产前诊断时,如父母一方携带α地中海贫血异常基因,尤其是携带基因型为-α4.2/αα基因时,如发现异常血红蛋白Q,有必要对产前诊断标本和父母血进行α珠蛋白基因测序分析。

Objective- To investigate the value of gene sequencing in prenatal diagnosis after detected HbH disease combining abnormal hemoglobin Q through case study. Methods： Four cases of fetal specimens and peripheral blood samples of their parents were analyzed by standard blood routine analysis, hemoglobin electrophoresis, Gap-PCR, reverse dot blot and DNA sequence. Results： Genotype of All the four fetuses were compound heterozygote of-SEA/--α4.2 and HBA1 CD74 G〉C. Abnormal hemoglobin Q-Thailand are inherited from their mothers. Conclusion： In prenatal diagnosis of α-thalassemia, if one of the parents carry -αthalassemia, especiallycarrymg-α4.2/ααgene, it is necessary to conduct gene sequencing of fetal and parents samples.