14 February 2011
ByAppeared in BioNews 595
A new study has demonstrated a genetic link to sleepwalking, a condition that affects up to ten percent of children and 1 in 50 adults.
The research team, based at Washington University School of Medicine, examined the DNA of 22 members of a family spanning four generations that contained nine sleepwalkers.
They found that a variant region of DNA on chromosome 20 was present in all of the nine sleepwalkers. This region is known to contain 28 genes, of which at least one is involved in slow-wave sleep, the stage of sleep in which sleepwalking occurs.
The report, published in the Journal of Neurology, is the first to demonstrate a link between a 'genetic locus' - a specific region of DNA - and sleepwalking, and has bolstered evidence that the condition has some degree of heritability.
Dr Caroline Gurnett, one of the lead authors, told the BBC: 'We do not know yet which of the genes in this linkage region of chromosome 20 will be responsible. Until we find the gene we won't know whether this accounts for several families or a large number of families who have sleepwalking'.
The researchers concluded that sleepwalking can be inherited in an 'autosomal with reduced penetrance' pattern - meaning that it is carried on the non-sex chromosomes and does not always manifest itself as a physical condition - which suggests that environmental factors and interaction with other genes may also be involved.