title: Sequencing of the ART4 gene in sub-Saharan cohorts reveals ethnic differences and two new DO alleles: DO*B-Ile5Thr and DO*B-Trp266Arg.
abstract: BACKGROUND
  Given the high heterogeneity of sub-Saharan populations especially between nonpygmoids and pygmoids, differences are expected during investigation of the DO/ART4 gene.
  
  
  METHODS
  Using genomic DNA extracted from blood samples collected from 77 Tswa pygmoids and 39 Teke and seven San nonpygmoids, DO coding regions were amplified and sequenced. A tetra-primer amplification refractory mutation system-polymerase chain reaction method was developed to specifically detect the DO*B-SH-Gln149Lys variant. Membrane expression of newly identified variant alleles in K562-transduced cells was studied by flow cytometry.
  
  
  RESULTS
  Extensive polymorphism was confirmed in Teke or San nonpygmoids and Tswa pygmoids with, respectively, 12, zero, and 24 DO*A; 54, 10, and 115 DO*B or DO*B-WL; five, zero, and 14 DO*HY; and six DO*JO alleles in Teke only. The DO*B-SH-Gln149Lys variant was observed as the third most frequent after the DO*HY and DO*JO alleles. Two novel DO*B alleles were identified in the San samples, that is, DO*B-Ile5Thr and DO*B-Trp266Arg. Study of K562-transduced cells showed that compared to the DO*B allele, DO*B-Ile5Thr was expressed more strongly while DO*B-Trp266Arg variant was expressed to a lesser extent and was not recognized by MIMA-123 monoclonal antibodies.
  
  
  CONCLUSIONS
  Sequencing analysis showed more allelic combinations in nonpygmoids than in pygmoids with high frequencies of DO*HY, DO*JO, and DO*B-SH-Gln149Lys variant alleles. This finding underlines the importance of including DO*HY and DO*JO single-nucleotide polymorphisms in genotyping tests to improve transfusion safety. Characterization of two novel DO*B alleles highlights the value of testing selected ethnic groups in understanding DO allele diversity.
authors.affiliation: Etablissement Français du Sang Alpes Méditerranée.|UMR 7268 ADÉS Aix-Marseille Université-EFS-CNRS, Marseille, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Durousseau de Coulgeans
authors.affiliation: Etablissement Français du Sang Alpes Méditerranée.|UMR 7268 ADÉS Aix-Marseille Université-EFS-CNRS, Marseille, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Chiaroni
authors.affiliation: Etablissement Français du Sang Alpes Méditerranée.|UMR 7268 ADÉS Aix-Marseille Université-EFS-CNRS, Marseille, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Bailly
authors.affiliation: Etablissement Français du Sang Alpes Méditerranée.|UMR 7268 ADÉS Aix-Marseille Université-EFS-CNRS, Marseille, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Chapel-Fernandes
mesh_terms: D036002:ADP Ribose Transferases / Q000235:genetics*; D017954:Africa South of the Sahara; D000483:Alleles; D044383:Black People / Q000208:ethnology* / Q000235:genetics*; D015331:Cohort Studies; D005260:Female; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D020014:K562 Cells; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*
chemical_list: D008565:Membrane Proteins; D036002:ADP Ribose Transferases; C105234:ART4 protein, human