title: Two novel missense mutations associated with hemophilia A in a family of Boxers, and a German Shepherd dog.
abstract: BACKGROUND
  Hemophilia A is an X-linked disorder caused by a deficiency in coagulation factor VIII. Over 2300 unique mutations in the gene-encoding factor VIII have been documented in people, but limited information is known in dogs. An 11-week-old male Boxer and a 5-year-old male German Shepherd were diagnosed with hemophilia A based on diminished factor VIII activity.
  
  
  OBJECTIVE
  The purpose of the study was to identify genetic mutations associated with hemophilia A in both dogs.
  
  
  METHODS
  Genomic DNA was isolated from EDTA blood samples from the affected German Shepherd and Boxer, the Boxer's dam, 3 female siblings, and one asymptomatic male sibling. Primers were designed in noncoding regions to amplify the 26 exons of the factor VIII gene via PCR.
  
  
  RESULTS
  The affected Boxer sequence revealed a single nucleotide change, cytosine to guanine, at nucleotide position 1412 (1412C>G) in exon 10. The change is predicted to result in the substitution of arginine for proline at amino acid 471 (P471R) in the A2 domain of factor VIII. The dam and female siblings were carriers, the male sibling did not have the mutation. The German Shepherd dog had a single nucleotide change of a guanine to adenine at position 1643 (1643G>A) in exon 11, predicting the substitution of tyrosine for cysteine at amino acid 548 (C548Y) in the A2 domain.
  
  
  CONCLUSIONS
  Here we document 2 mutations associated with canine hemophilia A associated with < 1% factor VIII activity, similar to that in people. Another related Boxer with the P471R mutation was later identified.
authors.affiliation: Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA.
authors.forename: Pete W
authors.initials: PW
authors.lastname: Christopherson
authors.forename: Lenore M
authors.initials: LM
authors.lastname: Bacek
authors.forename: Kevin B
authors.initials: KB
authors.lastname: King
authors.forename: Mary K
authors.initials: MK
authors.lastname: Boudreaux
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004283:Dog Diseases / Q000097:blood / Q000235:genetics*; D004285:Dogs; D005169:Factor VIII / Q000235:genetics* / Q000378:metabolism; D050172:Genes, X-Linked; D006467:Hemophilia A / Q000097:blood / Q000235:genetics / Q000662:veterinary*; D008297:Male; D020125:Mutation, Missense; D017422:Sequence Analysis, DNA
chemical_list: D005169:Factor VIII; D004247:DNA
keywords: Bleeding disorder; X-linked; coagulation; genetic; hemorrhage