Characterization of the mutations causing hemophilia B in 2 domestic cats.
The purpose of the present study was to determine the normal sequence for the gene encoding factor IX in cats and to characterize the genetic basis for hemophilia B in 2 unrelated male, domestic, mixed-breed cats. Genomic DNA sequence for the entire coding region of the factor IX gene was determined in the affected cats and compared to the sequence obtained from a healthy cat. The factor IX gene in cats encodes a mature protein consisting of 420 amino acids, unlike genes in humans and dogs that encode 415 and 413 amino acid proteins, respectively. Affected cat 1 had a single nucleotide change in exon 8 at the 1st nucleotide position of the codon encoding an arginine (CGA to TGA) at amino acid position 338. This mutation would be predicted to result in the appearance of a premature stop codon in the portion of the gene encoding much of the catalytic domain of the protein. Affected cat 2 had a single nucleotide change in exon 4 at the 2nd nucleotide position of the codon encoding amino acid 82 (TGT to TAT), which would be predicted to result in the substitution of a tyrosine for a cysteine. This substitution would likely result in disruption of a disulfide bond crucial to normal protein structure and function. This study represents the 1st time hemophilia B has been characterized at the molecular level in cats.
Goree
Michelle
M
Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849-5519, USA.
Catalfamo
James L
JL
Aber
Shelly
S
Boudreaux
Mary K
MK
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002371:Cat Diseases / Q000235:genetics*; D002415:Cats; D017124:Conserved Sequence; D005164:Factor IX / Q000737:chemistry* / Q000235:genetics; D002836:Hemophilia B / Q000235:genetics / Q000662:veterinary*; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D017386:Sequence Homology, Amino Acid
D005164:Factor IX