Gene therapy experts say they have found a way
to persuade cells to repair themselves.
Instead of
replacing a faulty gene, the new approach
harnesses the cells' own correctional
mechanisms.
German
researchers showed a drug could influence
the way a gene behaved in patients with a
debilitating genetic condition.
Details of the
research are being presented to the European
Society of Human Genetics conference in
Amsterdam.
The
research focussed on spinal muscular atrophy
(SMA), a relatively common inherited
disease, and the leading cause of death in
infants, affecting about one in every 6,000
newborns.
Due to degeneration of the motor neurons in
the spinal cord patients develop muscle
weakness and atrophy of the legs, arms and
trunk.
In patients with SMA the survival motor
neuron gene (SMN1) is deleted, but they all
carry a copy gene (SMN2).
However, this only produces about 10% of the
correct protein which is insufficient to
prevent the diseases.
The severity of the SMA is influenced by the
number of SMN2 genes, which normally vary
between one and four - the more copies there
are the better the patient fares.
'A small step'
However, it
remains unclear whether SMN expression in
blood reflects SMN expression in motor
neurons, and would therefore have an effect
on muscle strength.
But the
researchers said they hoped their findings
could have significant benefits in the
future.
Professor
Brunhilde Wirth said: "The long-term outcome
could be both improved therapy to enable a
better quality of life for SMA patients, and
also the introduction of neonatal screening
so that therapy could be started before the
first symptoms appear."
Dr Fred
Kavalier, of the British Society of Human
Genetics, said: "This work shows that it may
be possible to influence the behaviour of
genes with drugs.
"This is not a
cure for SMA, but it's a small step along
the road that may lead to an effective
treatment.
"It is exciting
to discover that a drug that is used to
treat epilepsy may also be helpful in a
completely different condition."
Professor Robin
Lovell-Badge, head of genetics at the
Medical Research Council's National
Institute for Medical Research, said it was
crucial to obtain detailed basic
understanding of specific genes, and the
nature of the defects responsible for
genetic disease before the knowledge was
applied to treating patients.
He added: "It
is still too early to say whether or how
well these particular approaches will work
in the clinic,.
"But the
preliminary results are encouraging and the
knowledge gained will hopefully generate yet
further tricks to bypass the unlucky set of
cards that some people are dealt."
