title: Characterization of three new deletions in the β-globin gene cluster during a screening survey in two French urban areas.
abstract: BACKGROUND
  Deletions represent about 5% of the mutations in the β-globin gene cluster. We report here the screening for such deletions in the two French urban areas of Paris and Lyon between 2003 and 2010.
  
  
  METHODS
  Semi-quantitative PCR methods were used for the first screening of deletions. Thereafter, a specific gap-PCR, eventually followed by DNA sequencing, was used for precise identification.
  
  
  RESULTS
  285 patients bore a deletion or recombination event in the β-globin gene cluster. Hbs Lepore or anti-Lepore were detected in 99 patients. Among the remaining 186 patients, 132 bore a deletion that could be fully identified. The most prevalent deletions were the Ghanaian HPFH-2 (n=46), the Sicilian (δβ)(0)-thal (n=22) and the Spanish (δβ)(0)-thal (n=12). The other characterized deletions were the: HPFH-3, HPFH-1, Filipino, Senegalese, Corfu, Kabilian, -1.39 kb, Indian -619 bp and -468 bp. Interestingly, three new deletions were fully characterized: a -7719 bp deletion, a -27,825 bp deletion with a 25 bp insertion and a -125 bp deletion.
  
  
  CONCLUSIONS
  The present study emphasizes the importance to detect deletions in the β-globin gene cluster, particularly for at risk couples. The new -27,825 bp deletion illustrates the complexity to understand the transcriptional regulation of fetal to adult hemoglobin switch.
authors.affiliation: Laboratoire de Génétique moléculaire, CHU Henri-Mondor AP-HP, and Université Paris Est Créteil (UPEC), Créteil, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Pissard
authors.forename: Valérie
authors.initials: V
authors.lastname: Raclin
authors.forename: Philippe
authors.initials: P
authors.lastname: Lacan
authors.forename: Caroline
authors.initials: C
authors.lastname: Garcia
authors.forename: Patricia
authors.initials: P
authors.lastname: Aguilar-Martinez
authors.forename: Alain
authors.initials: A
authors.lastname: Francina
authors.forename: Philippe
authors.initials: P
authors.lastname: Joly
mesh_terms: D000328:Adult; D001483:Base Sequence; D054242:Emigrants and Immigrants; D005260:Female; D005319:Fetal Hemoglobin / Q000235:genetics; D005602:France; D005820:Genetic Testing; D006306:Health Surveys; D006441:Hemoglobin A / Q000235:genetics; D006453:Hemoglobinopathies / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family; D016254:Mutagenesis, Insertional; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D014505:Urban Population; D055544:beta-Globins / Q000235:genetics*
chemical_list: D055544:beta-Globins; D006441:Hemoglobin A; D005319:Fetal Hemoglobin