Oliver Conway

The amount of testing that you have is like you have your brain scanned every year.

You have the rest of your body scanned every year.

You need ultrasounds of your stomach because these cancers can appear in multiple different organs within the body.

It is a life changing diagnosis for these families.

The donor isn't affected.

He acquired mutations and that has affected his sperm.

So most of his body does not contain this defective form of the TP53 gene, but around 20% of his sperm do carry the risk.

And it's really worth stressing in this that the donor was unaware.

As far as we understand, he was donating completely in good faith and didn't find out that he was carrying this mutation in his sperm until quite recently.

And are there other similar conditions that can be passed on unwittingly by donors?

Yeah, there is screening of sperm donors.

I mean, there is a reason why of the people that come forward for sperm donation, less than 5% of them are actually accepted.

And that's through screening of not only the sperm quality, but also for other genetic diseases.

Now, what the European Sperm Bank in Denmark has stressed as part of this is that overall, the risks from a sperm donor are

are lower than they are through normal conception, through meeting your partner-to-be, because the screening that is involved does reduce the risk.

But cases like this can still happen, and many fertility experts have said to me that it is going to be impossible to reach a world where you can screen for every single genetic disease that could possibly be passed down.

Our health and science correspondent, James Gallagher.

The winner of the Nobel Peace Prize, Maria Corina Machado, has been in hiding in Venezuela since accusing longtime president Nicolas Maduro of stealing the election last year.

So there was some doubt over whether she'd be able to leave her homeland to attend the Nobel Awards ceremony in the Norwegian capital, Oslo.

Well, in the event, Miss Machado didn't make it in time, but she released a statement saying she was on her way to the city.