It's every parent’s worst nightmare – watching their son or daughter collapse and die from a sudden heart attack. It was a nightmare that came into sharp focus when Cameroon midfielder Marc-Vivien Foe died during an international match in France this summer.

The supremely fit 28-year-old, who played for West Ham and Manchester City during his time in this country, fell to the ground during a televised match in front of a huge crowd in the 72nd minute of a Confederations Cup semi-final against Columbia.

He was stretchered off and given mouth to mouth resuscitation and oxygen, but 45 minutes of frantic efforts to restart his heart failed.

It traumatised the sporting world and reawakened tragic memories for the family of 14-year-old Ruth Salisbury, a pupil at the Beacon School in Banstead.

She was on holiday with her family at a New Forest holiday camp in October 1997 when she complained of feeling tired and dizzy. Shortly afterwards she collapsed and died.

Her family were devastated. Although her father’s cousin had died suddenly at the age of 14, her parents Tim and Silvia had never given a thought to sudden death among adolescents and young adults.

As they tried to come to terms with Ruth’s death, they learnt to their horror they were not alone – up to eight young people die suddenly in the UK every week from undiagnosed heart problems.

They also discovered 80 per cent of deaths among young competitive athletes are due to inherited congenital heart disease.

It was at this point they came across Cardiac Risk in the Young (CRY), a charity set up by Alison Cox, ex-wife of tennis star Mark Cox.

She founded the charity in 1995 when her son Steven, a tennis play with a promising future in the game, was diagnosed as having a major heart defect. If it had gone undetected it could have cost him his life.

He was on a sports scholarship at a huge American university when a fellow scholar collapsed and died without warning. The university tutors ordered all the sports scholars to undergo medical tests before taking part in any further exercise and Steven’s heart defect was discovered.

Terrified It was a traumatic time for Steve and his parents. “I was frightened, terrified. I was told he must never run across the road again,” says Alison.

“He asked how I would feel if he continued to play tennis. I had to work out how I would cope if he started playing again and dropped dead in front of me, but we gave him the freedom to make choices,” said Alison.

Steve decided to take medical advice, gave up sport and returned to the UK to reinvent his life and start a psychology degree at Surrey University.

Now 28, he works for CRY at its Tadworth based offices and is a vital part of the team set up to further research into heart defects, particularly testing for them and investigating the psychological effects of the tests.

Since CRY was set up, it has developed several areas of activity, promoting research into heart disease, raising awareness of sudden death syndrome – when a child or young adult suddenly dies without warning – and campaigning for a major screening programme to pick up genetic heart irregularities which can be carried through both the father and the mother.

It has also raised money to donate specialist equipment to surgeries and hospitals and runs a counselling programme to help parents coming to terms with the death of a child.

CRY is running a campaign to make doctors more aware of the rare heart conditions that can cause youngsters to feel dizzy or faint after exercise. Usually the symptoms are not significant but sometimes they can be the first sign something is very wrong.

With early diagnosis, youngsters can be treated and learn to take sensible precautions which allow them to live a normal life.

Some young athletes at the top of their respective sports are already tested at specialist CRY centres, but Alison wants the scheme extended much further, so every youngster has a routine electrocardiogram (ECG) test at about the age when they would normally have their BCG vaccination.

“What this would do is to pick up most, most but not all of the conditions we are trying to raise awareness of. It would make a major contribution to stopping these deaths in young people,” she says.

“People who carry the genetic condition can live all their life and never be troubled by it but they can pass it on to their children.

“One of the ethical problems we face is, is it right to tell someone they have a condition that will never affect them even though knowing about it will give them great anxiety?

“My answer is that it is ethical. Women say to me ‘if only I had known I was a carrier, I would have chosen not to have children and would have adopted’.

“They will say they believe this was their right, they should have had the freedom of choice and instead they have to confront the tragedy of losing a child and knowing they are the carrier of the gene that led to the death of their child.” She is convinced the cost of screening every youngster would be cost effective.

“You can’t quantify the cost of grief. Families sometimes become dysfunctional after such a death. You can have a serious collapse of a parent who finds they are a carrier of a gene that has just not killed one child but put the siblings at risk as well.” Ruth Salisbury’s mother Silvia has tried to turn her tragedy into something constructive.

She and her husband and son Tom, 17, moved to Cornwall last year for a change in lifestyle.

She adds: “You do understand so much more. Because of your experience you have something to offer people who are in the middle of it simply because you have been through it too.