Advanced reproductive technologies allow parents and doctors
to screen embryos
disorders and select healthy embryos.
In-vitro fertilisation or IVF
|The fear is that in the future
we may be able to use genetic technologies to modify embryos
and choose desirable or cosmetic characteristics. Designer
babies is a term used by journalists to describe this
frightening scenario. It is not a term used by scientists.
Advanced reproductive techniques involve using InVitro
Fertilisation or IVF
to fertilise eggs with sperm in 'test-tubes' outside the mother's
body in a laboratory. These techniques allow doctors and parents
to reduce the chance that a child will be born with a genetic
disorder. At the moment it is only legally possible to carry
out two types of advanced reproductive technologies on humans.
The first involves choosing the type of sperm that will fertilise
an egg: this is used to determine the sex and the genes
of the baby. The second technique screens embryos for a genetic
disease: only selected embryos are implanted back into the
mother's womb. This is called Pre-implantation Genetic
Recently scientists have made rapid advances in our knowledge
of the human genome
and in our ability to modify and change genes. In the future
we may be able to "cure" geneticy diseases in embryos
by replacing faulty sections of DNA
with healthy DNA. This is called germ line therapy
and is carried out on an egg, sperm or a tiny fertilised embryo.
Such therapy has successfully been done on animal embryos
but at present it is illegal to do this in humans.
However, it is legal to modify the faulty genes in the cells
of a grown child or an adult to cure diseases like cystic
fibrosis - this is called body cell gene therapy.