The parents of a two-year-old girl have to live in perfect peace – because any loud sudden noise could trigger an epileptic fit.

Blisse Mellens, two, suffers from a rare medical condition where any sudden noise could trigger an epileptic fit.

Her mother Laura and father Ashley watch their every movement, sneeze or cough to make sure their daughter isn’t startled by noise.

The youngster suffers from two rare brain conditions called polymicrogyria and Periventricular Nodular Heterotopia – and these trigger her epilepsy.

Laura, 27, said: ‘We have to think about every noise we make in the house every day. If you sneeze or cough you can make her fit. You have got to be absolutely quiet.

‘It is a startle reflex. If someone gets up suddenly or she hears your shoe on the floor it startles her.

‘I’ve even had to put my house phone put it on the low setting, because the ring can make her fit.’

The couple only discovered something was wrong after they took their daughter to a doctor when she began twitching at four months.

Blisse has a sister Neveah, eight, who knows she has to play ‘as quietly as she can’ to keep her safe.

One of the fits could be fatal – but most see Blisse slip into a trance like state that lasts about 20 seconds. The worst fits are called tonic-clonic seizures when Blisse turns blue and stops breathing.

Laura, of Barry, South Wales, treated her with emergency medicine to save her life during the worst attacks.

She said: ‘We have learned to be able to manage at home without ringing the ambulance. But it is devastating. The doctors have told us she is probably never going to speak or sit or walk.

‘We would love to hear what her voice is like and things like that but we have come to terms that that is not going to happen.

‘I communicate with her with her eyes. I can tell by the expressions on her face whether she is happy or sad.’

There is one alarm which rings out in the house – it is triggered if Blisse fits in her sleep.

Ashley and Laura then take turns to look after her while the other sleeps.

‘We have a nurse who comes one night a week so we have a full night sleep a week,’ said Laura.

‘It’s lovely. You just shut your eyes and when you wake up about 10 hours are gone. I don’t think we would cope without that.’

Doctors say she may live to adulthood, but is not likely to survive past 40.

But Laura said: ‘As long as she smiles, that is what gets us through the day. Her smile lights up her face.’