A daring attempt to use gene therapy to treat a rare, devastating
disorder that destroys the brains of children has shown signs of
slowing the disease's progression, according to a new paper. However,
some experts aren't convinced that the treatment, which involved
dripping a virus into young patients' brains, actually worked.
The children all have late infantile neuronal ceroid lipofuscinosis
(LINCL), a form of the neurodegenerative disorder Batten disease. They
were born without a working copy of CLN2,
a gene whose protein helps lysosomes--the cell's garbage-disposing
structures--break down a waste product called lipofuscin. As a result,
lipofuscin builds up and eventually destroy neurons, causing the brain
to shrink. Children with LINCL seem normal at birth but by age 2 to 4
show signs of developmental problems and often have seizures.
Eventually blind and confined to a wheelchair, they usually die by 8 to
12 years of age.
A few years ago, gene therapy researcher Ronald Crystal and colleagues
at Weill Cornell Medical College in New York City successfully slowed
LINCL in mice using gene therapy in the brain. To test the safety of
the approach in humans, the team treated 10 LINCL patients ranging in
age from 3 to 10 years, starting in 2004. After anesthetizing the
children, the researchers drilled six 2-mm-wide holes in their skulls.
They then dripped in a solution of a harmless virus that had been
modified to carry a good copy of the CLN2
gene. Four children had an immune response, but it was mild. One
patient developed seizures 2 weeks later and died 49 days after the
surgery. However, she did not have brain inflammation, and Crystal says
it was not clear whether her death had anything to do with the gene
therapy. Read More...