Let's talk aboutSleep Movement & Genetics

The science of sleep movement

Did you know that many people twitch multiple times throughout the night while they’re asleep? These involuntary twitches are called periodic limb movements, or PLMs. During sleep studies, researchers measure PLMs by placing electrodes on the arms and legs of a sleeping person.

The genetic link

Scientists have identified a genetic marker in the BTBD9 gene that impacts sleep movement. There are two possible versions of this marker: the A variant and the G variant. For each copy of the A variant a person has, they’re likely to move their limbs an additional 4-5 times per hour while sleeping, compared to people with two copies of the G variant.

Did you know?

The average person moves about 13 times an hour during sleep. But some people barely budge, and others may move more than 100 times per hour.

Explore more

Ever wondered how much you move in your sleep? 23andMe’s Health + Ancestry kit can tell you more about your own sleep movement. Order a kit and find out how much you’re likely to move in your sleep based on your genetics.

References

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Beard JL. (2001). “Iron Biology in Immune Function, Muscle Metabolism and Neuronal Functioning.” J Nutr. 131(2S-2):568S-579S.

DeAndrade MP et al. (2012). “Motor restlessness, sleep disturbances, thermal sensory alterations and elevated serum iron levels in Btbd9 mutant mice.” Hum Mol Genet. 21(18):3984-92.

Haba-Rubio J et al. (2016). “Prevalence and determinants of periodic limb movements in the general population.” Ann Neurol. 79(3):464-74.

Kripke DF et al. (2015). “Genetic variants associated with sleep disorders.” Sleep Med. 16(2):217-24.

Li J et al. (2015). “Association with low ferritin with PLM in the Wisconsin Sleep Cohort.” Sleep Med. 16(11):1413-8.

Moore H 4th et al. (2014). “Periodic leg movements during sleep are associated with polymorphisms in BTBD9, TOX3/BC034767, MEIS1, MAP2K5/SKOR1, and PTPRD.” Sleep. 37(9):1535-42.

NIH. “Iron: Dietary Supplement Fact Sheet: Sources of Iron.” NIH Office of Dietary Supplements.

Scofield H et al. (2008). “Periodic limb movements during sleep: population prevalence, clinical correlates, and racial differences.” Sleep. 31(9):1221-7.

Stefansson H et al. (2007). “A genetic risk factor for periodic limb movements in sleep.” N Engl J Med. 357(7):639-47.

U.S. National Library of Medicine. (2018). “BTBD9 gene.” Genetics Home Reference.