The putative factor IX gene promoter in hemophilia B Leyden
PH Reitsma, RM Bertina, JK Ploos van Amstel, A Riemens and E Briet
Department of Hematology, Leiden University Hospital, The Netherlands.
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.
Volume 72,
Issue 3,
pp. 1074-1076,
09/01/1988
Copyright © 1988 by The American Society of Hematology
