Li Youqiong, Chen Zhizhong, Zhao Lin, Wang Lin, Tian Mao, Huang Huayi, Qin Guifang, Chen Shiping
Department of Clinical Laboratory, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning 530021, China.
Zhonghua Xue Ye Xue Za Zhi. 2014 Aug;35(8):724-7. doi: 10.3760/cma.j.issn.0253-2727.2014.08.012.
To raise awareness of the pathogenesis and diagnosis of thalassemia by reporting one case of α thalassemia patient with a large deletion fragment and analyzing the pedigree.
Firstly, blood cells and hemoglobin electrophoresis analysis were used for screening of thalassemia, and then three common kinds of deletional α thalassemia in Chinese was detected by Gap-PCR, three common kinds of non- deletional α thalassemia and seventeen common mutations of β thalassemia in Chinese were analyzed by using PCR- RDB. The unknown mutation of samples was identified with Multiplex Ligation-dependent Probe Amplification (MLPA) and DNA sequencing.
The proband female presented with microcytic hypochromic anemia(hemoglobin 71 g/L, mean corpuscular volume 52.4 fl, mean corpuscular hemoglobin 16.1 pg), and hemoglobin A2 1.4%. The identified large deletion fragment length was 21 925 bp, so far which had not been reported in the world and was named -α²¹·⁹. It was registered in USA DNA database and GenBank accession number as KF360979. The genotype of her mother and father and brother were αα/-α²¹·⁹, --(SEA)/-α³·⁷, αα/-α³·⁷ respectively, and the genotype of her and her sister were the same of --(SEA)/-α²¹·⁹. Her husband gene of thalassemia had no mutation, so prenatal diagnosis of thalassemia was not carried out in the pregnant woman.
The discovery of -α(21.9) deletion mutation was enriched the DNA mutation gene database of thalassemia, and had important significance for genetic counseling and thalassemia prenatal diagnosis.
通过报告1例具有大片段缺失的α地中海贫血患者并进行家系分析，提高对地中海贫血发病机制及诊断的认识。
首先采用血细胞及血红蛋白电泳分析进行地中海贫血筛查，然后采用Gap-PCR检测中国人常见的3种缺失型α地中海贫血，采用聚合酶链反应-反向点杂交（PCR-RDB）分析中国人常见的3种非缺失型α地中海贫血及17种β地中海贫血常见突变。用多重连接依赖探针扩增技术（MLPA）及DNA测序鉴定样本的未知突变。
先证者女性表现为小细胞低色素性贫血（血红蛋白71 g/L，平均红细胞体积52.4 fl，平均红细胞血红蛋白含量16.1 pg），血红蛋白A2 1.4%。鉴定出的大片段缺失长度为21 925 bp，目前世界上尚未见报道，命名为-α²¹·⁹。已在美国DNA数据库注册，GenBank登录号为KF360979。其母亲、父亲及哥哥的基因型分别为αα/-α²¹·⁹、--(SEA)/-α³·⁷、αα/-α³·⁷，她和妹妹的基因型均为--(SEA)/-α²¹·⁹。其丈夫无地中海贫血基因突变，该孕妇未行地中海贫血产前诊断。
-α(21.9)缺失突变的发现丰富了地中海贫血DNA突变基因数据库，对遗传咨询及地中海贫血产前诊断具有重要意义。
