obsolete short sleeper true MONDO:0044278 OBSOLETE. In a review of various classification schemes for sleep disorders, {2: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.nnSee also familial advanced sleep-phase syndrome (FASPS; OMIM:604348), which is a distinct disorder characterized by very early sleep onset and offset. OMIMPS:612975 Obsoleted as it represents a trait or is a legacy entry