Lee Wilson was a happy and apparently healthy 19-year-old.  Then, one night, the teenager went to bed and never woke up.  Experts estimate that at least eight young people a week die from Sudden Adult Death Syndrome.  Chrissy Harris went to meet the people left to pick up the pieces....  

"I thought he was mucking around", says mum Carole Wilson, as she describes the moment she discovered her son dead in his bed. 

"I'd gone to wake him and I couldn't get any reaction.  I thought he was joking but then I realised he was cold to the touch. 

"I remember saying to myself, 'I think he's dead,' but I couldn't take it in.

"I went on auto-pilot and started thinking of really stupid things like how I'd better call his boss because he was supposed to be at work." 

More than two years after that dreadful day Carole, aged 46, still half-expects Lee to walk through the door. 

Lee, a sound and lighting technician at the Theatre Royal, died in his sleep, probably from Sudden Adult Death Syndrome (SADS), also known as Sudden Arrhythmia Death Syndrome, a condition similar to cot death. 

"It's an umbrella term used to describe many different causes of fatal cardiac arrest in people. 

But it's all people such as Carole have to explain why their loved one is gone. 

"It's such a broad thing and it's hard to take in because there were no symptoms," said Carole, who lives in Mount Gold with husband Steve, 48 and sons Wayne, 18 and Sam, 14. 

"Lee was never ill.  We had absolutely no warning. 

"Even if we had, there was nothing we could have done. 

"My husband and I have both said to each other, 'Why didn't we go and check on him?'  But why would we?  He'd just gone to bed like any other night."

SADS covers a broad range of heart conditions, many of which can lie undetected for years. 

Often there are no symptoms, but experts say in some cases people can experience dizziness or fainting spells. 

In addition, some of the cardiac abnormalities associated with SADS can be hereditary. 

How can you help?

Friends of Lee Wilson are running the London Marathon next month in his memory. 

Alistir Ellis, from St Jude's and Casey Knight, from Prince Rock, will be raising money for a charity called Cardiac Risk in the Young (CRY), which raises awareness of SADS and contributes to research. 

Alistair said: "We wanted to do it as a thank-you for the support the charity has given Steve and Carole. 

"Lee's death was such a shock to everybody."

To sponsor the pair visit www.just-giving.com/aliellis or www.justgiving.com/caseyknight

You can also send a cheque, payable to Cardiac Risk in the Young, to 20 Faringdon Road, St Judes, Plymouth PL4 9EP.

Susie's Murray is fighting to get this crucial information out and talked about to help prevent more families through the pain she has endured. 

Susie's 21-year-old daughter Nadine Bennett was found dead in her bed by her father, Alan.

The "brilliant, bright and loving" youngster had been talking to her boyfriend on her mobile phone when she died. 

"When someone's been poorly for a long time, you can come to terms with the fact they've gone, said Susie, 47, who lives near Gunnislake.

"When this happens, the shock leaves you absolutely reeling." 

Looking back, Susie says there were problems to suggest Nadine could have had a heart problem. 

The Duchy College student, who lived in Callington, had complained of feeling tired and had a couple of 'funny turns' where she felt faint.

Susie became concerned because her sister Dawn had died suddenly when the was just 33, apparently from SADS - and Susie had had a cardiac arrest when she was 23. 

Tragically, just when the alarm bells had started ringing, Nadine died. 

"You go through the guilt, the what-ifs; that's part of grieving," said Susie. 

"The truth is, no one can change what happened: but if we can reach someone out there - someone whose husband, son or daughter has been showing symptoms - then Nadine's death won't have been in vain. 

Susie, and her son Alex, 12, have each had an internal defibrillator fitted to help control their hear rates and perhaps sae their lives. 

Susie is also hoping to set up a support group in the Gunnislake/Callington area to help families who have lost loved ones and also care for those people living with heart conditions. 

"We need to raise awareness about this," she said. 

The staff at Derriford Hospital have been really supportive and there's a lot of good work going on there. 

"Things are changing, but it's a slow process." 

Susie said in the meantime the family was trying to get by without Nadine. 

It's been five years since she died.  We still talk about her every day," she said. 

"You never get over the loss; you just learn to live with it. 

"We decided together, though, that we could either let Nadine's death destroy us or we could let it make us stronger and try to prevent other people going through the same thing."