Thriving on Just Four Hours of Sleep? Science Says It's in the Genes

While most people need seven to nine hours of sleep each night, a rare few function optimally on just four—and now, scientists know why.

New research reveals that this remarkable ability is linked to a genetic mutation. Previous studies ⁽¹⁾ have identified the DEC2 gene associated with short sleep and five relevant mutations within those genes. A team at the University of California, San Francisco, discovered that a specific gene variant, SIK3-N783Y, is responsible for naturally short sleep in some individuals, a trait linked to lower-than-average sleepiness despite reduced sleep.

To study the gene’s effects, researchers created mice with the same mutation. These mice, like their human counterparts, required significantly less sleep than normal. On average, they slept about 31 minutes less daily, and even after sleep deprivation, they recovered with less sleep—around 54 minutes fewer.

Considering that mice usually sleep about 12 hours a day, the reduction is substantial. Brain scans showed that the mutated gene was active at neural synapses, suggesting it influences sleep by altering how proteins communicate in the brain. These findings deepen our understanding of sleep biology and may open doors to future treatments for sleep disorders. ⁽²⁾

Negative effects of sleep deprivation

Sleep is a vital biological function essential for physical and mental health. Chronic sleep deprivation can severely impact nearly every major system in the body. It supports the central nervous system by maintaining cognitive and emotional stability, and its absence can lead to serious safety risks like microsleeps. The immune system relies on sleep to fight infections, and chronic sleep deprivation weakens this defense. The respiratory system can both impact and be affected by sleep quality. In the digestive system, lack of sleep disrupts hunger hormones, encouraging overeating and increasing diabetes risk. Sleep also supports the cardiovascular system by regulating vital functions and reducing disease risk. Lastly, the endocrine system depends on sleep for hormone production critical to growth and repair, especially in youth. ⁽³⁾

Chronic sleep deprivation has widespread negative effects on the human body, affecting mental performance, immune function, metabolic processes, and cardiovascular health. Recognizing the importance of sleep and prioritizing sufficient, high-quality rest is essential for overall well-being and long-term health.

References:

1. Hongmin Chen “The SIK3-N783Y mutation is associated with the human natural short sleep trait” Proc Natl Acad Sci USA 2025 May 13; 122(19): e2500356122.

2. Ying He “The Transcriptional Repressor DEC2 Regulates Sleep Length in Mammals” Science 2009 Aug 14; 325(5942): 866–870.

3. Stephanie Watson, “The Effects of Sleep Deprivation on Your Body”, Health line, Last Modified on May 1, 2025. https://www.healthline.com/health/sleep-deprivation/effects-on-body

(Input from various sources)

(Rehash/Dr. Hansini Bhaskaran/MSM)