Scientists find genetic basis for sleepwalking

February 10, 2011 by Lin Edwards report

( -- Scientists studying a large family with four generations of sleepwalkers have traced the condition to one section of a single chromosome: chromosome 20, and have found that carrying just one copy of this defective section of DNA will make its carrier a sleepwalker.

Around one in 10 children are sleepwalkers and one in 50 adults. The condition, known as somnambulism, is usually benign but can be frightening and even dangerous, with some adult sleepwalkers even being able to find their keys and drive off in their cars while asleep.

Somnambulism is poorly understood. It generally occurs shortly after the person falls asleep, and takes place during a deep, non-dreaming, non-rapid eye movement phase characterized by slow brain waves. A sleepwalking episode usually lasts only a few minutes and it usually ends with the sleepwalker returning to bed, often without waking, and with no recollection the next day. Stress is a known trigger.

To learn more about the condition, scientists from the Washington University School of Medicine department of neurology, led by Dr Christina A. Gurnett, enlisted the aid of a family in which nine of the 22 members of the four generations were sleepwalkers, including Hanna, 12, who had been sleepwalking regularly, wandering outside the house during the night. One of Hannah’s uncles was also a sleepwalker, and regularly woke to discover he had donned eight pairs of socks while asleep. Some of the family had sustained injuries during sleepwalking.

The researchers carried out a genome-wide search to see if they could find a genetic basis for the condition. They found a section of the on chromosome 20 was related to sleepwalking: those who had the faulty DNA section sleepwalked, and those who did not were not sleepwalkers. A person with the condition had a 50 percent chance of passing it on to their offspring.

Dr Gurnett and the team have not yet identified the specific genes or gene involved, but think of the 28 or so likely candidates the most promising is the adenosine deaminase gene, which has been linked to the slow wave stage of sleep in which sleepwalking occurs. Since most people grow out of sleepwalking, Dr Gurnett said several genes are likely to be involved, and added that what the team had found was the “first genetic locus for sleepwalking.”

The paper was published in the journal Neurology. Future research will focus on identifying the exact gene or genes responsible for sleepwalking, since this may lead to ways of treating the condition. At present most cases are not treated because the drugs that are available have unwanted side effects.

Explore further: Sleep deprivation used to diagnose sleepwalking

More information: Novel genetic findings in an extended family pedigree with sleepwalking, by A.K. Licis, MD, et al., Neurology January 4, 2011 vol. 76 no. 1. doi:10.1212/WNL.0b013e318203e964

Related Stories

Sleep deprivation used to diagnose sleepwalking

March 19, 2008

Somnambulism (sleepwalking), which usually involves misperception and unresponsiveness to the environment, mental confusion and amnesia about sleepwalking episodes, affects up to 4 percent of adults. There has been a sharp ...

Lack of sleep can provoke sleepwalking

April 2, 2008

Sleepwalkers are advised to keep a regular bedtime to avoid unwanted evening strolls, according to research from the Université de Montréal. Somnambulism, which affects up to four percent of adults, can cause mental confusion ...

First gene for clubfoot identified

October 23, 2008

Clubfoot, one of the most common birth defects, has long been thought to have a genetic component. Now, researchers at Washington University School of Medicine in St. Louis report they have found the first gene linked to ...

Chromosomal abnormality found for inherited clubfoot

July 1, 2010

Although clubfoot is one of the most common congenital birth defects, few genetic causes have been found. Now, researchers at Washington University School of Medicine in St. Louis have found what they believe to be the most ...

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Cow embryos reveal new type of chromosome chimera

May 27, 2016

I've often wondered what happens between the time an egg is fertilized and the time the ball of cells that it becomes nestles into the uterine lining. It's a period that we know very little about, a black box of developmental ...

Shaving time to test antidotes for nerve agents

February 29, 2016

Imagine you wanted to know how much energy it took to bike up a mountain, but couldn't finish the ride to the peak yourself. So, to get the total energy required, you and a team of friends strap energy meters to your bikes ...


Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Feb 10, 2011
I'd be interested to see if they can find this gene (or a similar genetic marker) in sleep talkers
1 / 5 (1) Feb 10, 2011
It would be interested if this is also the cause of Somnaidiotism.

This is the characteristic of people whose brain is completely sleeping as soon as they begin talking, typing, or writing.

I suggest one way to determine this is systematic testing of politicians and frequent bloggers.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.