Faulty mitochondria effects about 15,000 babies every year and
prevents some tens of thousands of women from having children.
The US work, featured in the journal Nature, raises hopes of a
treatment enabling women with defective eggs to have a child
without using donor eggs. The treatment would involve so-called
"germ line" genetic changes which would be passed down through
generations. The genetic fault is contained in structures in the
egg called the mitochondria, which are involved in maintaining
the egg's internal processes. If an egg with faulty mitochondria
is fertilised the resulting child could have any of hundreds of
different diseases including anaemia, dementia, hypertension and
a range of neurological disorders. US researchers have
previously tried and failed to correct this defect by adding
healthy donated mitochondria into the eggs of patients wishing
to have children. But these attempts resulted in birth defects -
probably because mitochondria are so delicate that they are
damaged when they are