Researchers from Vrije Universiteit Amsterdam and elsewhere have identified seven risk genes for insomnia.

Insomnia is one of the most common health problems. Image credit: Dan Fa.

Insomnia is among the most frequent complaints in general practice. Even after treatment, poor sleep remains a persistent vulnerability for many people.

A research team led by Vrije Universiteit Professor Danielle Posthuma has come closer to unraveling the biological mechanisms that cause the predisposition for insomnia.

Our findings are the start of a path towards an understanding of insomnia at the level of communication within and between neurons, and thus towards finding new ways of treatment, Vrije Universiteit Professor Van Someren, co-author of the study.

As compared to the severity, prevalence and risks of insomnia, only few studies targeted its causes. Insomnia is all too often dismissed as being all in your head. Our research brings a new perspective. Insomnia is also in the genes.

To identify genetic factors for insomnia complaints, Prof. Posthuma, Prof. Someren and their colleagues performed a genome-wide association study and a genome-wide gene-based association study in 113,006 individuals.

As a result, the researchers identified seven genes associated with insomnia.

These genes play a role in the regulation of transcription, the process where DNA is read in order to make an RNA copy of it, and exocytosis, the release of molecules by cells in order to communicate with their environment, the authors said.

One of the identified genes, MEIS1, has previously been related to two other sleep disorders: periodic limb movements of sleep (PLMS) and restless legs syndrome (RLS).

Variants in the MEIS1 gene seem to contribute to all three disorders, they added.

Strikingly, PLMS and RLS are characterized by restless movement and sensation, respectively, whereas insomnia is characterized mainly by a restless stream of consciousness.

The team also found a strong genetic overlap with other traits, such as anxiety disorders, depression and neuroticism, and low subjective wellbeing.

This is an interesting finding, because these characteristics tend to go hand in hand with insomnia, said study first author Anke Hammerschlag, a PhD student at Vrije Universiteit.

We now know that this is partly due to the shared genetic basis.

The researchers also studied whether the same genetic variants were important for men and women.

Part of the genetic variants turned out to be different. This suggests that, for some part, different biological mechanisms may lead to insomnia in men and women, Prof. Posthuma said.

We also found a difference between men and women in terms of prevalence: in the sample we studied, including mainly people older than fifty years, 33% of the women reported to suffer from insomnia. For men this was 24%.

The teams findings were published today in the journal Nature Genetics.

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Anke R. Hammerschlag et al. Genome-wide association analysis of insomnia complaints identifies risk genes and genetic overlap with psychiatric and metabolic traits. Nature Genetics, published online June 12, 2017; doi: 10.1038/ng.3888

Read more:
Scientists Discover First Genes for Insomnia - Sci-News.com