Genetic Mutation Identified in Natural Short Sleepers

Not everyone requires the typical 7 to 8 hours of sleep to feel rested and function optimally. Some individuals can thrive on significantly fewer hours of sleep—sometimes as little as 4 to 6 hours—without experiencing negative effects, a trait believed to be linked to specific genetic mutations. A recent study has uncovered that a mutation in the gene salt-induced kinase 3 (hSIK3-N783Y) may be behind this phenomenon.

Published in the Proceedings of the National Academy of Sciences, the research highlights the role of the SIK3 gene, which is crucial for regulating sleep duration and depth. The study suggests that this mutation allows certain people, known as natural short sleepers (NSS), to bypass the usual consequences of sleep deprivation. While most humans need a full night’s sleep, NSS individuals often feel rested with fewer hours and may even experience worse feelings when sleeping longer.

The investigation involved examining a healthy 70-year-old volunteer who identified as a natural short sleeper. Despite self-reporting only 3 hours of sleep, actigraphy recordings showed an average of 6.3 hours per night. Genetic analysis revealed she carried the N783Y mutation in the SIK3 gene. To confirm its role, scientists bred mice with the same mutation, which then slept about 30 minutes less than typical mice. Structural analysis indicated that this mutation alters the SIK3 protein's ability to transfer phosphate groups, impacting sleep regulation.

Understanding such genetic factors is vital because sleep plays a key role in repairing cells, managing hormones, and supporting brain functions. Chronic sleep deprivation has been associated with increased risks of heart disease, diabetes, stroke, obesity, and depression. Insights into the genetics of sleep can pave the way for new treatments to improve sleep quality and combat sleep-related disorders.

This research underscores the evolutionary conservation of the SIK3 gene and its potential as a target for developing therapies to address sleep issues. Overall, these findings reveal how some individuals are naturally wired for shorter sleep durations without adverse health impacts, thanks to specific genetic mutations.