Daughter's sleepwalking 'frightening'
The typical bedtime routine in the Dulaney household is to lock, bolt and barricade the doors, and then hide the keys.
This is not simply to keep others out but rather to keep their soon-to-be teenage daughter in.
Hannah, aged 12, has a problem - once apparently safely asleep in her bed the wandering begins.
Like many other members of her family before her, Hannah is a sleepwalker.
And medical experts now believe it is a genetic trait she has inherited from her father, although her mother, Amy, was also a sleepwalker as a child.
Four generations of the Dulaney family took part in the research, conducted by Dr Christina Gurnett and colleagues at the Washington University School of Medicine in the US.
The family, from Missouri, were the ideal study group since nine of the 22 members were sleepwalkers.
Each volunteered to share their sleepwalking experiences and to have a sample of saliva taken for DNA analysis to look for any suspect genes that might explain their unusual nocturnal behaviour.
The test results revealed an inherited genetic error located on a small segment of chromosome 20.
In Hannah's case it has caused her to do some bizarre things in the middle of the night.
Her mother Amy said: "It was almost like clockwork - an hour and a half, two hours into her sleep. She would get up and she would flip on the lights. She would go through every room of the house.
"We would find her randomly walking through the house. We would then redirect her back to her bed and she would go back to sleep."
Other mornings Hannah would wake up to find herself fully dressed in her brother's clothes, after raiding his wardrobe in her sleep.
Sometimes her sleepwalking was accompanied by night terrors.
Mrs Dulaney says: "It was very unnerving when she would have night terrors and sleepwalk.
"She was extremely frightened as if something were standing there extremely terrifying. She would walk through the house screaming and her eyes wide open.
"Just to look into her eyes - it was like you could just look through her. It was very disturbing because it wasn't really her."
This happened every night for over a month, until an incident happened that prompted her parents to seek medical help.
"We got up early in the morning to leave the house and my daughter came to me and said 'mum where's my pillow?' She didn't know where to find it. Her blanket was missing too.
"Eventually, we found them in the back of my husband's truck.
"It was at that point that we realised she had gotten outside into the garage and had gotten into the truck, and we had no idea if she had slept in there or at what point she had come back into the house. That was really disturbing."
This started happening on numerous occasions and so Amy and her husband decided to put latches on all of the doors.
"The physicians advised us not to let her know how to operate the latches because anything she could do in the day she could replicate in her sleep.
"She tried to go out the front door at one point but we had the latches so it stopped her, thankfully, because there is a railway that runs close to our house."
Mrs Dulaney says she and her husband lost a lot of sleep through worrying about their daughter's behaviour.
"After we would get her back to bed we would worry that she could get up again. For a long time we went without a lot of sleep."
Hannah's sleepwalking has since improved a little, and her parents hope that it may be something she grows out of.
But given her family's history of sleepwalking well into adulthood, it could be something that stays with her.
Doctors who have studied the family's genetics believe the Dulaneys could be key to uncovering the root cause of all sleepwalking.
For now, their research shows Hannah her condition is something she was born with and has a 50-50 chance of passing on to her own children in the future.