RhD variants in Caucasians: consequences for checking clinically relevant alleles.
BACKGROUND
Weak D type carriers cannot be immunized against D except when antigen density is below 400 antigens per RBC, whereas partial D carriers can produce anti-D.


METHODS
A total of 168 blood samples from Caucasian individuals were studied because of weak D expression and/or anti-D production. Serologic analysis and molecular analysis were performed.


RESULTS
In total, 70 partial D and 62 weak D were identified. Among weak D samples, 30 weak D Type 1 and 21 weak D Type 2 alleles were found. Five new alleles were characterized carrying 399G > T, 680T > C, 833G > A, 851C > T, and 1015G > A, respectively. According to previous studies, antigen density was up to 500 for weak D Type 1 and 2, except when there was a dCe haplotype in trans. Antigen density was below 400 antigens per red blood cell for the new variants and most other weak D variants.


CONCLUSIONS
These results provide molecular characterization of five new D variants. They also suggest that it would be advantageous to develop in routine laboratories weak D Type 1 and 2 genotyping for serologically depressed D antigen. It will help to avoid wasting of D- red blood cell units because carriers may safely receive D+ units.
National Blood Group Reference Center and the French Establishment of Transfusion of Ile de France, Hôpital Henri Mondor, Créteil, France.
Hélène
H
Ansart-Pirenne
Marianne
M
Asso-Bonnet
Pierre-Yves
PY
Le Pennec
Michèle
M
Roussel
Claude
C
Patereau
France
F
Noizat-Pirenne
D000483:Alleles; D019943:Amino Acid Substitution; D001788:Blood Grouping and Crossmatching; D005838:Genotype; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D007518:Isoantibodies / Q000097:blood; D008958:Models, Molecular; D020125:Mutation, Missense; D017354:Point Mutation; D012203:Rh Isoimmunization / Q000517:prevention & control; D012204:Rh-Hr Blood-Group System / Q000235:genetics*; D018029:Rho(D) Immune Globulin; D044465:White People / Q000235:genetics*
D007518:Isoantibodies; C061961:RHO(D) antibody; D012204:Rh-Hr Blood-Group System; D018029:Rho(D) Immune Globulin; C026410:Rho(D) antigen