When Liam Derbyshire lays himself down to sleep, he might pray the Lord his soul to keep.
Without the help of a life-support machine to sustain his breathing, the 11-year-old boy might really die before he wakes.
During the day, the 11-year-old can consciously inhale and exhale, but at night, when consciousness fades away, his breathing stops.
"When Liam goes to sleep, his brain forgets to tell his lungs to breathe," said Dr Gary Connett, a pediatrican and respiratory consultant from Southhampton General Hospital, who has treated the boy since infancy.
The boy already has outlived all medical expectations. His parents, who live in the town of Gosport, Hampshire, were told Liam wouldn't live beyond six weeks.
"'Every day the doctors are amazed at how fit he is," said his mother, Kim Derbyshire. "He has defied all the odds."
"We have been very fortunate with Liam that he has had the life that he's got," she told the Portsmouth News, which first reported the story. "We always wanted him to have as normal a life as we could give him. He's exceeded all expectations."
Plugged in to a life support machine at night to stay alive, the boy also carries a battery-operated ventilator in case he falls asleep in the car or on a plane.
The family has spent thousands of dollars on electricity bills and even has installed emergency equipment in case of a power outage. So far, all his care has been covered by Britain's National Health Service.
"But the human costs in terms of commitment to getting him home and managing him have been enormous," said Connett.
"It's an amazing story, and he is fortunate to have lived this long," said Dr. Ramon Cuevas, a pediatrician and assistant professor of neurology at Vanderbilt University's Children's Hospital.
"This is a very rare condition, and I have only seen one case of it," he said. "Only in one in a couple hundred thousand kids are diagnosed with it."
Cuevas' patient died at the age of 4.
CCHS is a rare disorder of respiratory control of the autonomic nervous system caused by a mutation in the PHOX2B gene, according to the National Organization of Rare Diseases (NORD).
In addition to breathing, that unconscious system regulates involuntary body functions including heart rate, blood pressure, body temperature and body and bladder control.
Lungs and airways are normal, and daytime breathing, which can be controlled through the conscious part of the brain or cortex, is generally unaffected.
The disorder often is called by its more dramatic name -- Ondine's Curse, named for the epic German nymph who falls in love with a mortal. He swears that his daily breath is a testimony to her love. But when the man is unfaithful, the king punishes him by making him remember all his bodily functions.
When the mortal falls asleep he forgets to breathe and dies.
Babies often are diagnosed with the disorder when they have tendency to turn blue while sleeping or show signs of respiratory distress. Some die all of a sudden and are misdiagnosed as victims of sudden infant death syndrome, according to Cuevas.