Background: Factor XI (FXI) is a plasma protein that participates in the formation of blood clots.
Factor XI deficiency is autosomal recessive hereditary disorder that may be associated with excess
bleeding in Holstein cattle.
Methods: In this study, 225 Holstein cows reared in Turkey were screened in order to identify
FXI genotypes. DNA extractions were obtained from the fresh blood of the cows. Amplicons of
FXI exon 12 were obtained by Polymerase Chain Reaction (PCR), and analyzed by 2% agarose gel
electrophoresis stained with ethidium bromide. Additionally, all cows were confirmed by DNA
sequencing to determine whether or not there was a mutant allele.
Results: Carriers of the FXI deficiency have two DNA fragments of 320 bp and 244 bp in size. The
results of our study demonstrated that only four out of the 225 Holstein cows tested in Turkey
carried the FXI deficiency. The frequency of the mutant FXI allele and the prevalence of
heterozygous cows were found as 0.9% and 1.8%, respectively.
Conclusion: The DNA-based test determines all genotypes, regardless of phenotype or FXI
activity. The mutation responsible for the FXI deficiency had not been detected in Holstein cattle
in Turkey before prior to this study. The frequency of the mutant FXI allele needs to be confirmed
by carrying out further analyses on cattle in Turkey and the selection programs should be
developed to eliminate this genetic disorder.