Gene therapy is the insertion of genes into an individual's cells and tissues to
treat a disease, and hereditary diseases in which a defective mutant allele is
replaced with a functional one. Although the technology is still in its infancy,
it has been used with some success. Antisense therapy is not strictly a form
of gene therapy, but is a genetically-mediated therapy and is often considered
together with other methods.
On September 14, 1990 at the U.S. National
Institutes of Health W. French Anderson, M.D., and his colleagues R. Michael
Blaese, M.D., C. Bouzaid, M.D., and Kenneth Culver, M.D., performed the first
approved gene therapy procedure on four-year old Ashanthi DeSilva. Born with a
rare genetic disease called severe combined immunodeficiency (SCID), she lacked
a healthy immune system, and was vulnerable to every passing germ or infection.
Children with this illness usually develop overwhelming infections and rarely
survive to adulthood; a common childhood illness like chickenpox is life-threatening.
Ashanthi led a cloistered existence -- avoiding contact with people outside
her family, remaining in the sterile environment of her home, and battling
frequent illnesses with massive amounts of antibiotics.
In Ashanthi's
gene therapy procedure, doctors removed white blood cells from the child's
body, let the cells grow in the lab, inserted the missing gene into the cells,
and then infused the genetically modified blood cells back into the patient's bloodstream.
Laboratory tests have shown that the therapy strengthened Ashanthi's
immune system by 40%; she no longer has recurrent colds, she has been allowed
to attend school, and she was immunized against whooping cough. This procedure
was not a cure; the white blood cells treated genetically only work for a few
months, after which the process must be repeated (VII, Thompson [First] 1993).
As of early 2007, she was still in good health, and she was attending college.
....................................................More information
on Gene Therapy > Click Here |
