Genetic clue to sleepwalking

Up to 3% of adults sleepwalk

Scientists believe they may be a step closer to developing an effective treatment for sleepwalking.

It follows the discovery of a genetic marker which may make people susceptible to sleepwalking.

The condition affects around half of young children and up to 3% of adults.

Sleepwalking is a complex disorder

Dr Mahdi Tafti

Most incidents are harmless. However, in some cases people can injure themselves or others.

A team of European scientists examined a family of genes known as HLA genes.

They provide the information needed to allow the body to create immune cells.

Genetic test

They have also been linked to a number of sleep disorders, such as narcolepsy.

The scientists carried out tests on 60 people with a history of sleepwalking and 60 people without the condition to see if these genes also played a role in sleepwalking.

They found that people with the condition were 3.5 times more likely to have a sub-type, called HLA-DQB1.

They believe that this variation in their genetic make-up leaves them more susceptible to sleep-walking.

Dr Mahdi Tafti, a Swiss scientist involved in the study, said: "We found a strong association between the condition and this gene variation."

He added: "This is not a sleepwalking gene but if you have this variant, you have a 3.5 times higher risk of sleepwalking.

"The figure is even higher if there is a history of sleepwalking in your family."

However, speaking to BBC News Online he emphasised that sleepwalking was a complicated condition.

He said further research was needed before scientists could develop an effective treatment for the condition.

"Sleepwalking is a complex disorder, which is influenced by environment and stress. It is not a simple genetic condition," he said.

"We may in the future be able to use this information to develop treatments for sleepwalking."

The study is published in the journal Molecular Psychiatry.