United States Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, Nebraska, United States of America. mike.clawson@ars.usda.gov
BACKGROUND: Atypical bovine spongiform encephalopathies (BSEs) are recently recognized prion diseases of cattle. Atypical BSEs are rare; approximately 30 cases have been identified worldwide. We tested prion gene (PRNP) haplotypes for an association with atypical BSE. METHODOLOGY/PRINCIPLE FINDINGS: Haplotype tagging polymorphisms that characterize PRNP haplotypes from the promoter region through the three prime untranslated region of exon 3 (25.2 kb) were used to determine PRNP haplotypes of six available atypical BSE cases from Canada, France and the United States. One or two copies of a distinct PRNP haplotype were identified in five of the six cases (p = 1.3 x 10(-4), two-tailed Fisher's exact test; CI(95%) 0.263-0.901, difference between proportions). The haplotype spans a portion of PRNP that includes part of intron 2, the entire coding region of exon 3 and part of the three prime untranslated region of exon 3 (13 kb). CONCLUSIONS/SIGNIFICANCE: This result suggests that a genetic determinant in or near PRNP may influence susceptibility of cattle to atypical BSE.