A length polymorphism in the circadian clock gene Per3 is linked to delayed sleep phase syndrome and extreme diurnal preference.
OBJECTIVE
To investigate the link between extreme diurnal preference, delayed sleep phase syndrome, and a length polymorphism in Per3.


METHODS
Subjects were genotyped using polymerase chain reaction.


METHODS
Subjects with defined diurnal preference as determined by the Horne-Ostberg questionnaire and patients with delayed sleep phase syndrome.


RESULTS
The Per3 polymorphism correlated significantly with extreme diurnal preference, the longer allele associating with morningness and the shorter allele with eveningness. The shorter allele was strongly associated with the delayed sleep phase syndrome patients, 75% of whom were homozygous.


CONCLUSIONS
The length of the Per3 repeat region identifies a potential genetic marker for extreme diurnal preference.
Archer
Simon N
SN
Centre for Chronobiology, School of Biomedical and Life Science, University of Surrey, Guildford GU2 7XH, UK.
Robilliard
Donna L
DL
Skene
Debra J
DJ
Smits
Marcel
M
Williams
Adrian
A
Arendt
Josephine
J
von Schantz
Malcolm
M
D000293:Adolescent; D000328:Adult; D002755:Choice Behavior; D002940:Circadian Rhythm / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D009687:Nuclear Proteins / Q000235:genetics*; D056950:Period Circadian Proteins; D011110:Polymorphism, Genetic / Q000235:genetics*; D020178:Sleep Disorders, Circadian Rhythm / Q000235:genetics*; D011795:Surveys and Questionnaires; D014157:Transcription Factors
D009687:Nuclear Proteins; C512644:PER3 protein, human; D056950:Period Circadian Proteins; D014157:Transcription Factors