Hemophilia B Durham: a mutation in the first EGF-like domain of factor IX that is characterized by polymerase chain reaction.
Two men with factor IX (FIX)antigen-positive (CRM+) hemophilia B were selected for study because of their abnormal expression of an immunologically defined epitope previously localized to the EGF-like domains of the molecule. Exons IV and V (coding for the first and second EGF-like domains) of FIX were amplified 10(7) times from the patients' genomic DNA by using polymerase chain reaction (PCR) technology and sequenced. Both patients had identical mutations which resulted in the highly conserved Gly 60 residue being changed to Ser. PCR-amplified exon IV from six normal males had the previously defined canonic sequence. The correlation between the mutation and defective epitope expression in the two patients suggests that a change in the tertiary structure of the EGF-like domain is likely to cause the mild hemophilia B.
Denton
P H
PH
Department of Microbiology and Immunology, University of North Carolina, Chapel Hill 27599.
Fowlkes
D M
DM
Lord
S T
ST
Reisner
H M
HM
D000328:Adult; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D004259:DNA-Directed DNA Polymerase; D004815:Epidermal Growth Factor / Q000235:genetics*; D005164:Factor IX / Q000235:genetics*; D005784:Gene Amplification; D006467:Hemophilia A / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation
D004815:Epidermal Growth Factor; D005164:Factor IX; D004259:DNA-Directed DNA Polymerase