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0:00
The title of this talk is
Gene Therapy for Hemophilia.
My name is Katherine High, and
I'm a professor of pediatrics
at the University of
Pennsylvania School of Medicine
and an investigator of the
Howard Hughes Medical Institute.
0:18
I'll begin by providing
some background
on blood coagulation and hemophilia.
Hemophilia is the
x-linked bleeding disorder
that is caused by the absence of
functional factor VIII, which is
called hemophilia A, or factor
IX, which is called hemophilia B.
These diseases are
clinically indistinguishable
and were not separated in the
laboratory until the 1950s.
Both diseases are characterized
by frequent bleeding episodes,
primarily into the joints,
also other soft tissues,
and less frequently
but more seriously,
into critical closed spaces,
such as the intercranial space.
Hemophilia affects one
in 5000 male births,
with hemophilia A approximately
five to six times more common
than hemophilia B.
And clinically the disease is
divided into those who are severely
affected who have less
than 1% normal circulating
levels of factor VIII or factor IX.
Those who are moderately
affected with levels of 1% to 5%
and those who are mildly affected
with levels of 5% or greater.
1:31
For individuals who have never
seen a hemophilic knee bleed,
you can see in this slide
that the bleed can greatly
distend the joint, and
in fact, an untreated bleed
will continue to bleed until
the back pressure from the field
that joint space exerts enough
pressure to stop the bleeding.
It's easy to imagine that
this would be very painful
and that repeated bleeds
like this would result
in a chronic arthropathy
in the joint.
