In a review of various classification schemes for sleep disorders, Thorpy (1990) listed 'short sleeper' under the broad category of 'disorders of initiating and maintaining sleep' (DIMS); however, the short sleeper phenotype or trait is not considered a ... In a review of various classification schemes for sleep disorders, Thorpy (1990) listed 'short sleeper' under the broad category of 'disorders of initiating and maintaining sleep' (DIMS); however, the short sleeper phenotype or trait is not considered a sleep disorder. Individuals with this trait require less sleep in any 24-hour period than is typical for their age group. See also familial advanced sleep-phase syndrome (FASPS; 604348), which is a distinct disorder characterized by very early sleep onset and offset.
He et al. (2009) reported a mother and daughter with lifelong shorter daily sleep times than control individuals. The self-reported non-workday habitual sleep-offset times (awakening times) were much earlier than those of controls, although sleep-onset times (time of ... He et al. (2009) reported a mother and daughter with lifelong shorter daily sleep times than control individuals. The self-reported non-workday habitual sleep-offset times (awakening times) were much earlier than those of controls, although sleep-onset times (time of falling asleep) were similar to that of conventional sleepers. Per 24-hour day, the short sleepers slept an average of 6.25 hours compared with other family members who slept an average of 8.06 hours. Thus, the mother and daughter represented 'natural short sleepers.'