The Dc(G48)e(s) haplotype is frequent among the Dce haplotypes within a white population.
BACKGROUND
The absence of hybrid Rhesus boxes denotes an RHD homozygous status and helps to detect the presence of Dce haplotypes instead of dce. RHCE exon 1 C48, characteristic of RHC alleles, and RHCE exon 5 G733, responsible for VS antigenicity, have been noted in many RHce alleles but it was not clearly established whether they occurred in the same allele and/or cosegregate together with RHD.


METHODS
Samples from 148 white trios (father, mother, and child) were studied. Rh phenotype was performed by hemagglutination. Hybrid Rhesus box, RHCE exon 1 G48C, RHCE exon 5 C733G, and RHC intron 2 polymorphisms were analyzed by polymerase chain reaction. Haplotypes were determined considering serologic, molecular, and segregation data.


RESULTS
RHCE exon 1 C48 and RHCE exon 5 G733 were present in RHce alleles that cosegregated with RHD forming Dce haplotypes. Both transversions were not frequently found in the same RHce allele. Of the 33 Dce haplotypes, 16 (48.5%) had a C at position 48 [Dc(C48)e], 11 (33.3%) had a G at position 48 with a G at position 733 [Dc(G48)e(s)], 5 (15.2%) had a G at position 48 [Dc(G48)e], and 1 (3.0%) had a C at position 48 with a G at position 733 [Dc(C48)e(s)].


CONCLUSIONS
The results show four molecular backgrounds for the Dce haplotype and reflect the contribution of African alleles to the genetic pool of the population under study. The molecular characterization of Dce and its frequency distribution may develop a better understanding of the phylogeny of Rh haplotypes.
Cotorruelo
Carlos M
CM
Laboratory of Immunohematology Histocompatibility and Immunogenetics, Department of Clinical Biochemistry, Faculty of Biochemical and Pharmaceutical Sciences, Rosario National University, Rosario, Argentina. ccotorru@fbioyf.unr.edu.ar
Munini
Gabriel M
GM
García Borrás
Silvia E
SE
Racca
Liliana L
LL
Biondi
Claudia S
CS
Racca
Amelia L
AL
D001788:Blood Grouping and Crossmatching; D002648:Child; D005220:Fathers; D005787:Gene Frequency; D006239:Haplotypes; D006801:Humans; D009035:Mothers; D010375:Pedigree; D016133:Polymerase Chain Reaction / Q000379:methods; D020641:Polymorphism, Single Nucleotide; D012204:Rh-Hr Blood-Group System / Q000235:genetics*; D017422:Sequence Analysis, DNA; D044465:White People / Q000235:genetics*
D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen