DR MIRIAM STOPPARD.

Byline: DR MIRIAM STOPPARD

I FULLY sympathise with any family that wants to rid itself of a lethal gene.

Several years ago, I made a TV documentary on a family where the breast cancer gene ran through its female members, wreaking havoc with lives.

Then, the only way to cope with the resulting risk of breast cancer was to have prophylactic mastectomies and I filmed two sisters having them done and deciding if their daughters should do the same. What we see with pre-implantation genetic diagnosis is simply the next high-tech preventative measure.

It involves taking a cell from an embryo at the eight-cell stage, when it is around three days old, and testing it.

This is before conception - defined as when the embryo is implanted in the womb. There are ethical and moral questions when a couple weigh up whether to protect the baby this way but it's far better than having both breasts removed.

Advances always proceed faster than we adjust to them, but it would be quite wrong to turn our backs on this kind of new age treatment. In fact, I believe that it's going to become more and more common, though PGD is unlikely to eradicate serious conditions completely.