Deep Sleep May Be Genetic

Genes May Help Some People Sleep Deeper Than Others

From the WebMD Archives

Oct. 11, 2005 -- If you can sleep through a train wreck while your mate wakes up at the slightest disturbance, you may have your genes to thank.

A new study suggests that the key to deep sleep may be in the genes.

Researchers found that people with a certain genetic mutation had deeper, more intense sleep than people with the more common form of the gene. People with this genetic mutation also reported waking up less often during the night.

Meanwhile, the study also showed that a mutation in another gene in the same system, known as the adenosine system, was also related to sleep activity in the brain.

Deep Sleep May Be in the Genes

Researchers say sleep intensity is related to sleep need. Previous studies in animals have suggested that genetic factors may play a role in determining the need for sleep, but the specific genes involved in this process in humans are not known.

In the study, published in the Proceedings of the National Academy of Sciences, researchers looked at the link between differences in sleep-related brain activity and genetic differences in how the body responds to adenosine.

First, they found people with a mutation on the adenosine deaminase gene had deeper, more intense sleep than people with the more common type of the gene. They also reported fewer sleep disturbances during the night.

Second, the study showed that people with a mutation in another adenosine-related gene (the adenosine A2A receptor) had altered brain activity during sleep and while awake. People with this genetic mutation also responded differently to caffeine.

Studies have shown that caffeine blocks the drowsy effects of adenosine in the brain.

Therefore, researchers say that these findings show that genetic differences in the adenosine system may explain some of the variation in sleep need and quality found in humans. Whether these findings suggest some role in people with insomnia problems needs to be further studied, write the researchers.

WebMD Health News Reviewed by Louise Chang, MD on October 11, 2005

Sources

SOURCE: Rétey, J. Proceedings of the National Academy of Sciences, Oct. 10, 2005 online early edition.
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