深圳市科技创新委员会科技计划( KJY Y20180703173402020 )
摘要:目的对血红蛋白组分 出现疑似异常血红蛋白Q-Thailand( HbQ-Thailand).且存在小细胞低色素性表现的2例患者进行基因型鉴定,并分析其血液学参数特征,为临床遗传咨询提供参考数据。方法2例患者样本进 行血液学指标检测,用跨越断 裂点聚合酶链反应( Gap-PCR)及Sanger测序方法进行珠蛋白基因突变检测,并分析2例患者血液学表型特征和血红蛋白毛细管电泳结果。结果患者 1为HbQ-Thailand杂合合并a-地贫-a“2缺失杂合和β-地贫Taiwanese型缺失杂合,患者2为 HbQ-Thailand杂合合并-a4.2缺失杂合和β-地贫°γ°(^γδβ)°型缺失杂合;2例患者均表现为小细胞低色素表型特征，并存在血红蛋白毛细管电泳Z7条带增高及出现Z1区异常带。结论当 HbQ-Thailand 合并β-地贫基因缺失时，血红蛋白组分毛细管电泳分析中HbQ-Thailand与HbF重疊,需要对其进行鉴别,或同时进行β-地贫基因缺失检测以防漏检。
Abstract: Objective To identify the genotypes of two patients with suspected abnomal hemoglobin Q-Thailand( HbQ-Thailand) and microcytic hypochromic anemia, and analyze the characteristics of their hematological parameters, so as to provide reference data for clinical genetic counseling. Methods The hematological indexes of two patients were detected. The mutations of globin gene were de- termined by Gap-PCR and Sanger sequencing. Meanwhile, the hematological phenotypic characteristics and capillary electrophoresis of hemoglobin results of the two patients were analyzed. Results The genotype of patient 1 was the heterozygous deletion of -a4.2 Q-Th. in/aa combined with β /βawanes, and that of patient 2 was the heterozygous deletion of -a'4.2-Q-Thailand I /axx combined with β "/β'Gr+(Ay8B)0 Their hematological characteristics showed microcytic hypochromic anemia and elevated Z7 band and abnormal Z1 band in the capillary electrophoresis of hemoglobin. Conclusion When HbQ-Thailand is combined with deletional β-thalassemia, HbQ-Thailand overlaps with HbF in the capillary electrophoresis of hemoglobin, which requires the identification or simultaneous analysis of deletional β-thalassemia to avoid a misdiagnosis.