A 16-year-old boy had a heart attack while playing Sonic The Hedgehog on his Xbox.
Jake Gallagher suddenly keeled over while playing the game. He was revived by paramedics but declared brain dead after two days on life support.
Doctors told his devastated mum Sarah Pyatt, 46, that Jake had Sudden Arrhythmic Death Syndrome - like footballer Fabrice Muamba who recovered after 'dying' on the pitch.
She believes a surge of excitement playing the video game could have triggered Jake's undiagnosed condition.
Sarah said: "Sonic The Hedgehog was his favourite. He would get over-excited, jumping up and down, screaming at the screen."
Jake died on a visit to his grandmother Irene Gallagher, 72, in April. Paramedics started his heart again and he was taken to Watford General Hospital. But doctors said his brain had been starved of oxygen which made it unlikely he would survive.
Professor Sanjay Sharma of St George's Hospital, South West London, told The Sun: "There is a definite risk in predisposed young people playing video games that cause surges of adrenalin in the blood."
Jake, who had Aspergers, had not had heart screening, which costs £25.
Mum Sarah, from Dunstable, Beds, has now joined charity Cardiac Risk in the Young to encourage screening.
She said: "Screening should be mandatory for all young people. It's so important families are aware - then they can avoid losing their child like I lost Jake."