FY*X real-time polymerase chain reaction with melting curve analysis associated with a complete one-step real-time FY genotyping.
OBJECTIVE
The Duffy (FY) blood group system is controlled by four major alleles: FY*A and FY*B, the Caucasian common alleles, encoding Fy(a) and Fy(b) antigens; FY*X allele responsible for a poorly expressed Fy(b) antigen, and FY*Fy a silent predominant allele among Black population. Despite the recent development of a real-time fluorescent polymerase chain reaction (PCR) method for FY genotyping FY*X genotyping has not been described by this method. This study focused on the real-time FY*X genotyping development associated with a complete, one-step real-time FY genotyping, based on fluorescence resonance energy transfer (FRET) technology.


METHODS
Seventy-two blood samples from Fy(a+b-) Caucasian blood donors were studied by real-time PCR only. Forty-seven Caucasian and Black individual blood samples, referred to our laboratory, were studied by PCR-RFLP and real-time PCR. For each individual, the result of the genotype was compared to the known phenotype.


RESULTS
The FY*X allele frequency calculated in an Fy(a+b-) Caucasian blood donors population was 0.014. With the Caucasian and Black patient samples we found a complete correlation between PCR-RFLP and the real-time PCR method whatever the alleles combination tested. When the known phenotype was not correlated to FY*X genotype, the presence of the Fy(b) antigen was always confirmed by adsorption-elution.


CONCLUSIONS
The real-time technology method is rapid and accurate for FY genotyping. From now, we are able to detect the FY*X allele in all the alleles combinations studied. Regarding its significant frequency, the detection of the FY*X allele is useful for the correct typing of blood donors and recipients considering the therapeutic use of blood units and the preparation of test red blood cells for antibody screening.
Ansart-Pirenne
H
H
Institut National de la Transfusion Sanguine, Centre National de Référence pour les Groupes Sanguins, 20 rue Bouvier, 75522 Paris cedex 11, France.
Martin-Blanc
S
S
Le Pennec
P-Y
PY
Rouger
P
P
Cartron
J-P
JP
Tournamille
C
C
D044383:Black People / Q000235:genetics*; D001782:Blood Donors; D004375:Duffy Blood-Group System / Q000145:classification / Q000235:genetics*; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D044465:White People / Q000235:genetics*
D004375:Duffy Blood-Group System