The putative factor IX gene promoter in hemophilia B Leyden.
Hemophilia B Leyden is characterized by low levels of factor IX antigen and activity before the age of 15, whereas after puberty factor IX levels rise at a rate of about 5% per year. A single base substitution (-A----T) at position -20 was identified in the putative promoter of the gene cloned from a patient with hemophilia B Leyden. This nucleotide change was confirmed in a second patient from the same pedigree and was also found in a patient from a second Dutch pedigree with the same hemophilic phenotype. The results indicate that the two Dutch kindreds are related and point to the functional significance of the -20 position for the expression of the human factor IX gene.
Reitsma
P H
PH
Department of Hematology, Leiden University Hospital, The Netherlands.
Bertina
R M
RM
Ploos van Amstel
J K
JK
Riemens
A
A
Briët
E
E
D000328:Adult; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D005164:Factor IX / Q000235:genetics* / Q000302:isolation & purification; D002836:Hemophilia B / Q000235:genetics*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009426:Netherlands; D009710:Nucleotide Mapping; D011401:Promoter Regions, Genetic
D005164:Factor IX