Meet Liam Derbyshire. He's a 17-year-old who suffers from a rare condition called Central Hypoventilation Syndrome. His illness means that if he falls asleep unaided, he could die. Liam, who is from Gosport, South Hampshire has to be connected to a life-support machine and observed every time he settles into bed. The conditions also goes by the name Ondine's Curse; it's known to effect only 1,500 people around the world and causes the patients lungs to stop functioning while asleep. It can also cause damage to heart rate, blood pressure and other vital organs like the brain. His mother Kim says: " Central Hypoventilation Syndrome basically implies that when you sleep, your phrenic nerve doesn't kick in so your brain doesn't tell you to breathe. We rely on a machine to make him breathe and without that, he wouldn't be alive. If he doesn't breathe, he dies - that's it. " On top of this, Liam also suffers from an unrelated bowel condition as he was born with a large part of the organ missing, forcing him to use an ileostomy bag as a replacement. The journey that he and his family have been on so far has understandably not been easy, and every night brings concern for his father, Peter. " If you ask me if I had a good night sleep the answer is no, not since the day he was born to be quite frank. You're constantly on alert and worry that perhaps it’s the last time you are saying good night. " Liam still manages to attend a regular school, enjoys drawing, building things out of LEGO and has a keen interest in trains. The other miraculous thing about Liam is that he has survived with the condition since he was born, defying the odds of doctors who originally only gave him six weeks to live. Now, Liam is just months away from turning 18 and he is like every other teenager that came before him. Kim adds: " He is an annoying, grumpy teenager so he is no different to any other teenager but he does have a sense of humour and he is very caring - he's got a really soft side. You can't regret anything you have done - we've had 18 years of his life so day to day you can't regret anything. " While this is a momentous occasion for Liam and his family, including his older brother and two sisters, his father still feels that the future is uncertain for his son. " We have gone from nothing towards 18. The future for Liam I would say is, it's not going to be totally independent. I mean to a certain extent he has been protected by his own condition that he doesn't understand certain things. I'm extremely proud of him. I personally would have given up a long time ago. I couldn't have lived with the condition he has and put up with what he has with the pain levels. " To learn more about Liam, his condition and his family, you can watch the short video from Barcroft media below. source for more informations about Congenital Central Hypoventilation Syndrome