There is an article in the October 26th issue of Neurology where researchers studied normal sleep and sleep-deprivation, and determined if participants had a certain gene variant (DQB1*0602). Patients with that gene variant were sleepier and more fatigued while sleep-deprived or even while fully rested. These individuals also woke up more often at night and spent less time in deep sleep than those without the gene variant. However, there was no difference on tests of memory and attention, or in their ability to resist sleep during the day.
The authors explained that their findings mean there might be a genetic biomarker to predict how people will respond to sleep deprivation. This has significant health consequences and affects millions around the world. It may be particularly important in those work night shift, travel frequently across multiple time zones, or just don't sleep enough due to multiple work and family obligations.
This gene variant has already been implicated in narcolepsy, a sleep disorder characterized by excessive sleepiness, despite adequate amounts of sleep at night.