At the beginning of this year, three months after the birth of their daughter Lia, north Londoners Lauren and Richard Kayser discovered they were both Tay-Sachs carriers.

They then had to get Lia tested and waited an agonising two days before receiving the all clear.

Mrs Kayser said she had no idea about Jewish genetic conditions until she was 28 weeks pregnant, when a friend shared her story.

Her friend had only discovered that she and her husband were carriers when she was pregnant, and terminated the pregnancy.

"She bravely shared that story, which prompted me and a lot of others to go and get tested. Still, at the time I was thinking: 'It is a horrific situation but the likelihood of it happening to us is minimal.'

"I was completely freaked out though, because I was already well into the point of pregnancy where it would have been too late to do anything. I was pretty shocked that I'd got to that point in my life and had no idea any of these diseases existed - even Tay-Sachs, which is supposed to be the one that everyone knows about. I went to a university with a large Jewish student population, I was a part of the J-Soc, I had a big circle of Jewish friends. But still it just hadn't got through to me."

A week after Lia was born, a screening took place at the couple's shul, Stanmore Synagogue, and Mr Kayser went along to get tested.

When the results showed he was a Tay-Sachs carrier, she went to Guy's to be tested.

"My results didn't come back for a week but friends kept reassuring us: 'Don't be so silly, don't stress out, the likelihood is so minimal.'

"Then we got a call from Guy's at eight o clock the next Monday morning saying: 'We're really sorry but you've also come back as a carrier and you need to bring your daughter Lia for emergency testing.'

"I feel sick just thinking about that moment. It's a complete blur.

"Somehow we got in the car to go to the hospital. We were both complete wrecks. It was just horrendous.

"We had to wait two days for the results but it felt like an eternity. It was literally 48 hours of agony. We were blaming ourselves. Why had we not heard about these diseases and these screenings? Was it something that maybe had been told to us at some point and we had just ignored it?

"When Sarah, the genetics counsellor, came into the room where we were waiting 48 hours later, we could tell straightaway by her facial expression that it was fine. At that point there was just complete elation. We had Lia with us and we were just looking at her thinking: 'She's going to live; she doesn't have this horrific disease.'

"We know that in terms of having future children it's not going to be the easiest path. But there are options for us. And we just feel so very lucky we've got a healthy child. Not a day goes by where we're not grateful.

"But if my friend hadn't shared her story, if Jnetics weren't doing the great work they're doing in terms of promoting these events and trying to get them on people's radar… myself and my husband could have gone through another pregnancy not knowing and, God forbid, that could have ended in a completely different situation.

She added: "Knowledge is power and we will do everything we can to support Jnetics to try and make sure no one ever finds themselves in the situation we were in – or obviously worse, because we were very lucky. We'd just never want to ever hear about anyone else going through this or something else like this.

What is surprising is that, even now, there are people who have heard about our situation and are still thinking: 'It can't happen to me.'

"But this is not something we can ignore. It's a reality for our community."