title: Comprehensive analysis of RHD alleles in Argentineans with variant D phenotypes.
abstract: BACKGROUND
  The serologic assignment of the RhD status may be hindered in patients with weak D expression. A comprehensive study of RHD alleles occurring in the mixed population of Argentina is necessary to evaluate the most suitable DNA typing strategy.
  
  
  METHODS
  A total of 18,379 patients from two stratified groups, Group 1 (G1; public hospital) and Group 2 (G2; private laboratory), were RhD phenotyped, and 88 samples with reduced D expression underwent molecular characterization.
  
  
  RESULTS
  The frequencies of D+, D-, and variant D phenotypes differed significantly (p < 0.001) between G1 and G2 (94.49% vs. 87.66%, 5.15% vs. 11.58%, and 0.36% vs. 0.75%, respectively). Eleven alleles were responsible for the weak D expression. Approximately 60% of the variant D phenotypes from G1 and G2 were weak D Types 1 through 4.0/4.2 and 25% were DVII. RHD alleles associated with African ancestry were encountered in G1. A new -282G>A mutation within the promoter region of DAU-4 and DOL alleles was identified. Three weak D Type 1 samples on R(0) haplotypes were found in G1.
  
  
  CONCLUSIONS
  The D phenotype distribution in G2 resembles that in Europeans while the frequencies in G1 account for the Amerindian and African genetic contribution. The genotyping strategy described here is suitable to study D variants in the overall population and could allow a better use of the few available D- units and a rational administration of anti-D immunoprophylaxis. The results also show that weak D Type 1 alleles do not exclusively segregate with a Ce allele, as assumed until present.
authors: Laboratorio de Inmunohematología e Inmunogenética, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
authors: Melina E Luján
authors: ME
authors: Brajovich
authors: Carolina Trucco
authors: CT
authors: Boggione
authors: Claudia S
authors: CS
authors: Biondi
authors: Amelia L
authors: AL
authors: Racca
authors: Marcel
authors: M
authors: Tarragó
authors: Núria
authors: N
authors: Nogués
authors: Eduardo
authors: E
authors: Muñiz-Díaz
authors: Carlos M
authors: CM
authors: Cotorruelo
mesh_terms: D000328:Adult; D000465:Algorithms; D000483:Alleles; D001118:Argentina / Q000453:epidemiology; D001803:Blood Transfusion / Q000706:statistics & numerical data; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation / Q000502:physiology; D005828:Genetics, Population; D005838:Genotype; D006801:Humans; D008297:Male; D058889:Molecular Typing / Q000379:methods; D010641:Phenotype; D011247:Pregnancy; D012204:Rh-Hr Blood-Group System / Q000235:genetics*
chemical_list: D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen