Take too many naps and have trouble waking up on time? You can now blame your genes! Scientists have found some people are simply born to nap. 

Dr Hassan Saeed Dashti of the MGH Center for Genomic Medicine, co-lead a report with Iyas Daghlas, a medical student at Harvard Medical School (HMS), and sampled the genetic information from 452,633 people to find out what makes them snooze. 

Source: Photo by Andrea Piacquadio from Pexels

Participants were asked how often they napped during the day and were given three choices - never/rarely, sometimes or usually. Following which, a genome-wide association study (GWAS) was then carried out to identify genetic variations associated with napping. Which identified 123 regions in the human genome, which were associated with napping during the day.

This tells us that daytime napping is biologically driven and not just an environmental or behavioural choice.

                    - Dr Hassan Saeed Dashti

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They identified three potential napping mechanisms:

Sleep propensity: Some people need more shut-eye than others. 

Disrupted sleep: A daytime nap can help make up for poor quality slumber the night before. 
Early morning awakening: People who rise early may “catch up” on sleep with a nap.

Some of the genetic traits identified were also linked to health concerns, including obesity and high blood pressure. 

This pathway is known to be involved in rare sleep disorders like narcolepsy, but our findings show that smaller perturbations in the pathway can explain why some people nap more than others.

                    - Iyas Daghlas

Source: Photo by Andrea Piacquadio from Pexels

So the next time someone asks you why you're constantly falling asleep in the middle of the day? Tell them your body simply needs it and it's in your genes!