title: [Analysis of clinical phenotype and genotype of unstable Hemoglobin Rush].
abstract: OBJECTIVE
  To analyze the hematological and genetic characteristics of unstable hemoglobin Rush (Hb Rush) and compound heterozygote of Hb Rush and thalassemia.
  
  
  METHODS
  Peripheral blood samples and genomic DNA from three patients (including two ethnic Dai and one Han Chinese) with anemia of undetermined origin were collected. Hematological phenotypes of these patients were determined through red blood cell analysis and hemoglobin electrophoresis. Genotypes of alpha- and beta-globin genes, -158 XmnⅠ polymorphic site ofGγ promoter region, and haplotypes of 7 polymorphic restriction sites in the beta-globin gene cluster were determined using PCR-based methods and DNA sequencing.
  
  
  RESULTS
  All patients have presented hypochromic microcytic anemia and hemoglobin fraction with significant increased measurement (30.5%-59.2%) in the region of fetal hemoglobin during alkaline medium electrophoresis. DNA analysis suggested that all patients have carried mutations leading to the unstable hemoglobin Rush (HBB codon 101, GAG>CAG, Glu>Gln). Two of them were compound heterozygotes of Hb Rush and thalassemia mutations of -α3.7,CD17 and Hb E, respectively. Hb Rush mutation was associated with various haplotypes of the β-globin gene cluster. No significant association was found between increased abnormal hemoglobin fraction in the region of Hb F and the polymorphism ofGγ promoter or large deletion of the beta-globin gene cluster.
  
  
  CONCLUSIONS
  This study has confirmed the distribution of Hb Rush among various Chinese populations and is the third report of its kind. Hb Rush can result in increased measurement of hemoglobin fraction in the region of fetal hemoglobin (Hb F) during routine hemoglobin electrophoresis under alkaline condition. Hb Rush heterozygote alone can lead to hypochromic microcytic anemia and thalassemia-like phenotype. Prenatal diagnosis of Hb Rush is necessary for carriers.
authors.affiliation: Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Kunming, Yunnan 650118, China. zyang@imbcams.com.cn.
authors.forename: Shijun
authors.initials: S
authors.lastname: Ge
authors.forename: Biqing
authors.initials: B
authors.lastname: Yang
authors.forename: Wei
authors.initials: W
authors.lastname: Yi
authors.forename: Kai
authors.initials: K
authors.lastname: Huang
authors.forename: Hongxian
authors.initials: H
authors.lastname: Liu
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Huang
authors.forename: Jiayou
authors.initials: J
authors.lastname: Chu
authors.forename: Zhaoqing
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000328:Adult; D001483:Base Sequence; D001797:Blood Protein Electrophoresis / Q000379:methods; D005260:Female; D005319:Fetal Hemoglobin / Q000235:genetics / Q000378:metabolism; D005838:Genotype; D006239:Haplotypes; D006455:Hemoglobins, Abnormal / Q000235:genetics* / Q000378:metabolism; D006579:Heterozygote; D006801:Humans; D007223:Infant; D009154:Mutation; D010641:Phenotype; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA / Q000379:methods; D013789:Thalassemia / Q000097:blood / Q000175:diagnosis / Q000235:genetics*; D055815:Young Adult; D055542:alpha-Globins / Q000235:genetics / Q000378:metabolism; D055544:beta-Globins / Q000235:genetics / Q000378:metabolism
chemical_list: C000620913:Hemoglobin Rush; D006455:Hemoglobins, Abnormal; D055542:alpha-Globins; D055544:beta-Globins; D005319:Fetal Hemoglobin