Sleep is a global state and its control mechanisms are manifested at every level of biological organization- from genes and intracellular mechanisms, to networks of cell populations, to phenotypes at the organismal level. They include (but are not limited to) arousal, motor control, autonomic function, behavior, and cognition. We live in a sleep deprived society. Prolonged sleep loss impairs temperature control, dietary metabolism, immune function, and eventually leads to death. Sleep deprivation increases an individual's risk of cancer, metabolic syndrome, psychiatric, and other disorders. Understanding the biological basis of sleep in humans is an extremely difficult challenge since the biological determinants of our sleep are affected by behavior and other factors including life-style choices, socio-economic status, health, employment, school, and exogenous chemicals like caffeine and alcohol. Sleep and circadian function are distinct processes that interact in living organisms. Sleep is controlled by at least two processes: a circadian pacemaker (the clock) ticking with periodicity of ~24 hours, and a homeostatic drive that increases during wakefulness and dissipates during sleep. Despite of the fact that we spend around one third of our life in the state of sleep, we understand almost nothing about regulatory mechanisms governing sleep quantity. A unique opportunity presented itself when we identified independent families with a dramatically reduced biological need for sleep. Identification of new subjects and expanding our collection of these families will establish a foundation for us to begin probing the molecular regulatory mechanisms of sleep homeostasis. Recently, we reported the first mutation that causes this short-sleep phenotype. Interestingly, this mutation gave a similar short sleep phenotype in human, mouse, and fly. All the genes identified in this study will therefore become entry points for us to unravel the enigmatic sleep related mechanisms. Ultimately, combining the knowledge from studies in multiple genes and in humans and model organisms will lead to a better understanding of sleep and its relationship to health and disease.

National Institute of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
Research Project (R01)
Project #
Application #
Study Section
Genetics of Health and Disease Study Section (GHD)
Program Officer
He, Janet
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of California San Francisco
Schools of Medicine
San Francisco
United States
Zip Code
Zhang, Luoying; Fu, Ying-Hui (2018) The molecular genetics of human sleep. Eur J Neurosci :
Hirano, Arisa; Hsu, Pei-Ken; Zhang, Luoying et al. (2018) DEC2 modulates orexin expression and regulates sleep. Proc Natl Acad Sci U S A 115:3434-3439
Shi, Guangsen; Wu, David; Ptá?ek, Louis J et al. (2017) Human genetics and sleep behavior. Curr Opin Neurobiol 44:43-49
Zhang, Luoying; Hirano, Arisa; Hsu, Pei-Ken et al. (2016) A PERIOD3 variant causes a circadian phenotype and is associated with a seasonal mood trait. Proc Natl Acad Sci U S A 113:E1536-44
Kaasik, Krista; Kivimäe, Saul; Allen, Jasmina J et al. (2013) Glucose sensor O-GlcNAcylation coordinates with phosphorylation to regulate circadian clock. Cell Metab 17:291-302
Hallows, William C; Ptá?ek, Louis J; Fu, Ying-Hui (2013) Solving the mystery of human sleep schedules one mutation at a time. Crit Rev Biochem Mol Biol 48:465-75
Jones, Christopher R (2013) Diagnostic and management approach to common sleep disorders during pregnancy. Clin Obstet Gynecol 56:360-71
Kurien, Philip A; Chong, S Y Christin; Ptá?ek, Louis J et al. (2013) Sick and tired: how molecular regulators of human sleep schedules and duration impact immune function. Curr Opin Neurobiol 23:873-9
Jones, Christopher R; Huang, Angela L; Ptá?ek, Louis J et al. (2013) Genetic basis of human circadian rhythm disorders. Exp Neurol 243:28-33
Chong, S Y Christin; Ptá?ek, Louis J; Fu, Ying-Hui (2012) Genetic insights on sleep schedules: this time, it's PERsonal. Trends Genet 28:598-605