title: [Analysis of copy number variations in alpha-globin gene in the cases with combined increased levels of HbF with β thalassemia].
abstract: OBJECTIVE
  To detect copy number changes of α-globin gene, and analyze molecular mechanism of the impacts of fetal hemoglobin (HbF) levels for α-globin gene copy numbers loss or increase.
  
  
  METHODS
  A total of 15 cases with combined increased levels of fetal hemoglobin with β-thalassemia were collected. Firstly, three common α-thalassemia deletions were validated by Gap-PCR. Secondly, the largest deletions of the β-globin gene cluster were detected by multiplex ligation-dependent probe amplification (MLPA).
  
  
  RESULTS
  Among the 15 cases, there was 1 case with duplication of the α-globin gene cluster, 3 cases of SEA heterozygote deletion of the α-globin gene, 1 cases of α 3.7 deletion heterozygote of the α-globin gene, 1 case of alpha 4.2 deletion homozygote of the α-globin gene, 1 case of deletion homozygote in the like α-globin gene. A compound heterozygous for SEA and α 3.7 of the α-globin gene was also detected. However, 7 cases showed no copy numbers loss and increase of the the α-globin gene cluster.
  
  
  CONCLUSIONS
  Additional α-globin gene can produce excessive α-chain, which can aggravate imbalance for α and β-chain, and cause clinical symptoms in patients with β-thalassemia. Yet, copy number loss or mutation in α-globin gene will cause a milder clinical phenotype.
authors.affiliation: Technology Center of Prenatal Diagnosis and Genetic Diseases Diagnosis, Department of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P. R. China. shenhong2010168@163.com; drmzhong@gmail.com.
authors.forename: Siping
authors.initials: S
authors.lastname: Liu
authors.forename: Lanlin
authors.initials: L
authors.lastname: Song
authors.forename: Li
authors.initials: L
authors.lastname: Xiong
authors.forename: Ke
authors.initials: K
authors.lastname: Wang
authors.forename: Hong
authors.initials: H
authors.lastname: Shen
authors.forename: Mei
authors.initials: M
authors.lastname: Zhong
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics; D002681:China; D056915:DNA Copy Number Variations; D005260:Female; D005319:Fetal Hemoglobin / Q000378:metabolism*; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation; D010375:Pedigree; D055542:alpha-Globins / Q000235:genetics*; D017086:beta-Thalassemia / Q000235:genetics* / Q000378:metabolism
chemical_list: D055542:alpha-Globins; D005319:Fetal Hemoglobin