Rapid haplotyping of mutations in the Duffy gene using the polymerase chain reaction and sequence-specific primers.

The molecular basis for the antigenic variation and red cell expression of the Duffy antigen system has recently been elucidated. We have developed a simple one-step method for genotyping the single nucleotide polymorphisms in the promoter and exon of the Duffy gene using the polymerase chain reaction and sequence-specific primers (PCR-SSP). This method is also capable of haplotyping alleles at the two polymorphisms as being in cis or trans orientation. Twenty-four serologically typed Caucasoid and Afro-Caribbean samples were examined to validate the method, with absolute correlation between phenotype and genotype. A further 30 Gambian samples were genotyped, confirming homozygosity for the FY*null-FY*B haplotype. Allele, gene and haplotype frequencies were examined in 100 Caucasoid controls. This method permits the rapid genotyping of large numbers of samples and will prove useful as a clinical and research tool.