THREE PARENTS BABY

'Three people, one baby' public consultation begins

The technique could be used to prevent debilitating and fatal "mitochondrial" diseases, which are passed down only from mother to child.

However, the resulting baby would contain genetic information from three people - two parents and a donor woman.

About one in 200 children are born with faulty mitochondria - the tiny power stations which provide energy to every cell in the body.

Most show little or no symptoms, but in the severest cases the cells of the body are starved of energy. It can lead to muscle weakness, blindness, heart failure and in some cases can be fatal.

Mitochondria are passed on from the mother's egg to the child - the father does not pass on mitochondria through his sperm. The idea to prevent this is to add a healthy woman's mitochondria into the mix.

Two main techniques have been shown to work in the laboratory, by using a donor embryo or a donor egg.

How do you make a baby from three 

people?

1) Two embryos are fertilised with sperm creating an embryo from the intended parents and another from the donors. 

2) The pronuclei, which contain genetic information, are removed from both embryos but only the parents' is kept 

3) A healthy embryo is created by adding the parents' pronuclei to the donor embryo, which is finally implanted into the womb

Step 1. Eggs from a mother with damaged mitochondria and a donor with healthy mitochondria are collected.

 Step 2. The majority of the genetic material is removed from both eggs.

 Step 3. The mother's genetic material is inserted into the donor egg, which can be fertilised by sperm

However, mitochondria contain their own genes in their own set of DNA. It means any babies produced would contain genetic material from three people. The vast majority would come from the mother and father, but also mitochondrial DNA from the donor woman.

This would be a permanent form of genetic modification, which would be passed down through the generations.

It is one of the ethical considerations which will be discussed as part of the Human Fertilisation and Embryology Authority's consultation.

Source: http://www.bbc.co.uk