The son and daughter of a young mother who died of sudden death syndrome have been diagnosed with the same disease.

Four-year-old Liam Belger and his baby sister Ella were screened for the rare heart defect cardiac arrhythmia following the death of their 21-year-old mum Amanda, of Plas Porth, Uchaf, Conwy.

A London-based cardiologist also carried out specialised ECG tests on Mandy's close family and relatives, but results showed that her two children were the only ones found to have long QT syndrome.

It is the latest in a series of setbacks for the Belgers. Last year the Weekly News reported how police wrongly blamed Mandy's death on heroin overdose, following speculation over a batch of rogue drugs circulating in the Caernarfon area where she was found dead.

Her mother Sandra Arm­strong said North Wales Police admitted the mistake, hut she is yet to receive an apology.

Since Mandy’s death, Sandra and her husband, Dr Godfrey Armstrong have sold her business on Conwy High Street and moved to Llandudno Junction for a new start with Liam and Ella.

“Obviously this is tragic news, but it’s fortunate we found out sooner rather than later - at least we will now be able to control the disease.” said Sandra.

“So few people know about this terrible illness, which is why I am going to make it my mission to travel around schools, youth clubs and colleges to spread the word and expose long QT syndrome.

“Liam and Ella will have to live with this for the rest of their lives, and I’m sure there are dozens of other youngsters and adults in North Wales who have cardiac arrhythmia but don’t know it.”

Long QT syndrome is a rare inherited disorder, which affects the heart’s electrical system.

People with this condition have longer than normal inter­vals between certain beats.

The disease can kill in an instant and is triggered by a shock, such as a loud bang or fright, when a person is sleeping or relaxed. It kills up to eight people a week in the UK, yet it is alleged the Government will not fund vital £35 tests until the death toll hits double figures.

Once long QT is diagnosed, it can be controlled with medica­tion or with a pacemaker which detects when the heart has gone into fibrillation (uncontrolled quivering), and brings it back to normal.

Alison Cox, spokeswoman for Cardiac Risk in the Young, is sympathetic to their problems and applauds Sandra and Godfrey for their bravery.

“This is an extension of the terrible tragedy they experienced last year”, she said.

“Raising awareness, which Sandra is focused on doing, is the single most cost-effective way of saving people’s lives.

“It must be horrible to know your grandchildren have the same illness your child died of.  It may not be curable but it can be treated.”