Gene Therapy Pages:
gene therapy (main)
gene therapy FAQ
gene therapy articles (HemAware)
gene therapy trials
Gene therapy represents a new field of medicine, one which can potentially
cure many genetic diseases such as bleeding disorders. Patients with inherited
diseases such as hemophilia usually lack a functional protein, which can
be replaced with periodic protein replacement therapy. An alternative
is to add a normal gene to substitute for the defective one. The normal
gene, if delivered to the right cells and in sufficient quantity, can
continuously make the normal version of the defective protein, restoring
normal clotting mechanisms.
However, this is a new and highly experimental field. Many questions remain
unanswered and will only be answered through a series of clinical studies,
some of which are ongoing using the genes for factors VIII and IX. There
have been many failures and disapointments when investigators have found
that the technology for delivering the genes was inadequate when used
in humans. Sometimes investigators have underestimated the complexity
of the diseases they were attempting to cure. Because of some recent successes,
hemophilia has emerged as the top candidate for a genetic disease most
likely to benefit from gene therapy.
Hemophilia is considered an ideal disease for gene therapy because it's
caused by a single malfunctioning gene, and only a small increase in clotting
factor in the bloodstream could provide great medical benefits. If gene
therapy raises levels of missing clotting factors by as little as 2% of
normal, it is enough to prevent patients from suffering spontaneous hemorrhages
into joints, brain and other organs, as happens with hemophilia. Levels
greater than 20% to 30% would be sufficient to prevent bleeding in all
but the most traumatic injuries.
Although gene therapy could potentially replace treatment for hemophilia,
it only corrects the defect in the hemophilic individual, not in their
genetic line. Affected individuals would still pass hemophilia to their
Treatment that would correct the defect in all cells, including reproductive
cells, is called germline therapy. It would have to be done at the embryo
stage of conception. There are many ethical considerations that will need
to be addressed before germline therapy is attempted in humans.
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information only. NHF does not give medical advice or engage in the practice
of medicine. NHF under no circumstances recommends particular treatment
for specific individuals and in all cases recommends that you consult your
physician or local treatment center before pursuing any course of treatment.
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