一个携带罕见的2.4kb缺失型α地中海贫血基因家系的研究

Analysis of an individual and his family carrying 2.4kb deletional alpha-thalassemia gene

目的罕见α地贫缺失型基因的漏检,会给地中海贫血产前诊断工作带来风险。研究组对一例地贫检测中基因型与血液学检测数据不匹配的个体进行罕见地贫分析,同时采集其家系辅助分析,以阐述其分子生物学机制。方法采用商品化地贫基因检测试剂盒实施常规地贫基因分析,罕见地贫分析方法采用测序法、实验室自研qPCR体系、MLPA、Gap-PCR法等完成。结果先证者样本中检出-α2.4地贫基因,家系分析验证了这是一个携带-α2.4地贫基因的家系。结论-α2.4地贫基因在南方地区人群有一定的分布频率。国内地贫检测机构所使用的常规地贫基因检测试剂盒的检测范围并未包含-α2.4地贫基因,地贫基因检测机构在实施地贫基因分析时,应密切留意受测者血液学数据与基因分析数据的匹配性,避免相对少见的地贫基因的漏诊。

Objective:The missed detection of novel alpha-thalassemia gene would bring risks to the prenatal diagnosis of thalassemia.The research team analyzed a thalassemia screen positive individual whose genotype did not match the hematological data in thalassemia detection.And,samples from his family were collected for analysis to elucidate its molecular biological mechanism.Methods:The commercialized thalassemia gene detection kits were selected to perform routine thalassemia gene analysis.Sequencing,self-developed q-PCR system,MLPA and Gap-PCR were used for novel thalassemia gene analysis.Results:The 2.4kb deletional alpha thalassemia gene was detected in the sample of probands.Pedigree analysis confirmed that it was a family 2.4kb deletional alpha thalassemia gene.Conclusion:The 2.4kb deletional alpha thalassemia gene has a certain distribution frequency in the southern population of China.The detection range of the routine gene detection kit used by the domestic detection agencies for thalassemia does not contain the 2.4kb deletional alpha thalassemia gene.When peform the genetic analysis for thalassemia,the genetic detection agencies should pay close attention to the matching of hematological data and genetic analysis data of the subjects,to avoid the missed diagnosis of novel thalassemia gene.