A mutation analysis on GYPC, the gene encoding the Gerbich blood group antigens

The four exons of GYPC genomic DNA were amplified together with their flanking sequences and analysed by denaturing gradient gel electrophoresis (DGGE) or single-strand conformational analysis (SSCA). Exons 2 and 3 were amplified by a common set of primers so as to provide an internal control for exon deletion mutants. Ge:-2,-3,4(Ge) and Ge:-2,3,4(Yus) phenotypes were always associated with exon 3 and exon 2 deletions, respectively, as determined by DGGE. Ge:-2,-3,-4(Leach) was associated with a deletion of exons 3 and 4. Two single base mutations within exon 2 were detected, one of which represented the Ana allele and encoded an amino acid substitution. A previously undetected single base mutation in exon 3 encoded a Val61Ile substitution within the membrane spanning domain. DGGE analysis of exon 4 product revealed two distinct haplotypes of frequencies 41% and 59%. DGGE was not found suitable for analysis of exon 1, so SSCA was utilized. This method distinguished the single base mutation responsible for Wb antigen, but not that responsible for Dha.