title: [Prevalence and molecular analysis of β-thalassemia in children of Han ethnicity in Chongqing city].
abstract: OBJECTIVE
  To investigate the incidence and the gene mutation frequencies and patterns of β-thalassemia (β-Thal) in ethnic Han children in Chongqing city.
  
  
  METHODS
  A total of 1726 children were screened by using automatic hemocytic analyzer, cellulose acetate electrophoresis and fetal hemoglobin alkali denaturation test. Samples with mean corpuscular volume (MCV) < 80 fl, cell hemoglobin content (MCH) < 27 pg and hemoglobin A2 (HbA2) levels >3.3%, fetal hemoglobin (HbF) >2% for β-Thal screening indicators. The positive samples of screening indicators were detected and identified by PCR-reverse dot blot method for 18 common β-Thal mutations in Chinese populations, unknown mutations samples were subjected to DNA sequencing analysis of the β-globin gene.
  
  
  RESULTS
  Twenty-five cases of β-Thal carriers were observed from the 1726 samples, with 24 cases of β-Thal heterozygote and one case of double heterozygote. Therefore, the β-Thal carrier rate was 1.51%. After 1726 peripheral venous blood samples analyzed by hematological parameters, 164 positive cases of β-Thal screening indicators were found, with the positive rate being 9.50% (164/1726). A total of 6 different gene mutations were detected, the four most common mutations were as the following: CD41-42, IVS-II-654, CD17 and beta E. These four mutations as the major types in this area accounted for 88.00% of all the mutations. In addition, one rare mutation of 5 'UTR; + (43 -40) was found, and one case of the hemoglobin variant of Hb Zurich was reported in Chinese people for the first time.
  
  
  CONCLUSIONS
  Chongqing is a high risk region of the β-Thal. Epidemiological Data from the research was useul for the genetic counseling and the prevention of β-Thal major.
authors.affiliation: Department of Hematology, Children's Hospital of Chongqing Medical University, Chongqing 400014, China.
authors.forename: Xiu-yun
authors.initials: XY
authors.lastname: Yao
authors.forename: Yu-mei
authors.initials: YM
authors.lastname: Zhang
authors.forename: Zhen-zi
authors.initials: ZZ
authors.lastname: Qin
authors.forename: Rong
authors.initials: R
authors.lastname: Fan
authors.forename: Lin
authors.initials: L
authors.lastname: Zou
authors.forename: Shi-ping
authors.initials: SP
authors.lastname: Chen
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Qian
authors.initials: Q
authors.lastname: Xie
authors.forename: Xiao-yun
authors.initials: XY
authors.lastname: Zhong
authors.forename: Ying
authors.initials: Y
authors.lastname: Xian
authors.forename: Jie
authors.initials: J
authors.lastname: Yu
mesh_terms: D044466:Asian People / Q000235:genetics; D001774:Blood Chemical Analysis; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D005260:Female; D005787:Gene Frequency; D005817:Genetic Counseling; D006454:Hemoglobins / Q000032:analysis / Q000235:genetics; D006455:Hemoglobins, Abnormal / Q000032:analysis / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation / Q000235:genetics; D015995:Prevalence; D055544:beta-Globins / Q000235:genetics; D017086:beta-Thalassemia / Q000453:epidemiology* / Q000208:ethnology / Q000235:genetics*
chemical_list: D006454:Hemoglobins; D006455:Hemoglobins, Abnormal; D055544:beta-Globins