Knowledge of the cat AB blood group system is important in specifically cat transfusion studies, as antigen mismatching can cause acute hemolytic transfusion reactions. Such reactions occur when naturally occurring alloantibodies in the serum react with the antigens of the cat blood types A, B, and AB which are expressed on the surfaces of red blood cells.
Mutations of CMAH gene have been reported in the blood type B cats. In our previous study, we found a blood type B cat with genotype revealed in blood type A. Then, we show here the detailed genomic structure of CMAH gene in this case
The nucleotide sequences of the coding region and 5'UTR of the CMAH gene were determined direct sequence analysis from genomic DNA in blood type B cat with genotype of AA. Blood types were determined using RapidVet-H Feline Blood Type cards.
We redetermined the CMAH genotypes of 6 SNPs (5'UTR nt-217, 5'UTR nt-371, Ex2 nt139, Ex3 nt265, Ex4 nt324, and Ex13 nt1600) and 1 indel (5'UTR nt-53) in a blood type B cat, which showed the homozygous haplotype revealed in blood type A. In addition, we found the missense mutations in the coding region of the CMAH gene. The haplotype was suggested to heterozygous.
The determination of the blood type by DNA testing needs further study for genetic association between CMAH variants and phenotypes in cats.