Objective: To evaluate whether a variable number tandem repeat (VNTR) in the human PER3 gene is linked with sleep or circadian phenotypes. Methods: Seventy three people (age: 23-71; 41 males and 32 females) volunteered for this study. They completed a questionnaire containing the Romanian translations of the Composite Scale of Morningness, the Sleep Disorders Questionnaire, the Pittsburgh Sleep Quality Index, the Pittsburgh Insomnia Rating Scale, the Epworth Sleepiness Scale, the Multidimensional Fatigue Inventory, the Alcohol Use Disorders Identification Test and the Beck Depression Inventory II. Genotyping was performed on genomic DNA in blood. Results: Sixteen subjects had the shorter allele (PER3 4/4), thirty one the longer one (PER3 5/5), while the rest were heterozygote (PER3 4/5). We found no statistically significant differences between the genotypes on any of the scales used. Conclusions: In this small population, PER3 genotype predicted none of the investigated variables.
Voinescu, B., Coogan, A., & Thome, J. (2010). P02-235 - PER3 VNTR as a predictor of sleep and diurnal preference in a Romanian population. European Psychiatry, 25, 858. https://doi.org/10.1016/s0924-9338(10)70849-x