Association between specific diurnal preference questionnaire items and PER3 VNTR genotype

Area of Science:

• Chronobiology
• Human Genetics
• Sleep Science

Background:

• Diurnal preference, or chronotype, shows significant individual variation.
• The genetic underpinnings, particularly the PER3 gene's variable number tandem polymorphism (VNTR), are linked to chronotype.
• Exogenous and endogenous factors influencing diurnal preference require further investigation.

Purpose of the Study:

• To identify specific items in the Horne-Ostberg (HO) questionnaire that predict PER3 genotypes.
• To explore the association between PER3 VNTR polymorphism and self-reported diurnal preference.
• To understand the role of genetic factors in diurnal preference variation.

Main Methods:

• Genotyping of the PER3 VNTR polymorphism in 240 participants.
• Analysis of self-reported diurnal preference using the Horne-Ostberg (HO) questionnaire.
• Multinomial logistic regression to assess prediction accuracy of HO items for PER3 genotypes.

Main Results:

• Four HO questionnaire items significantly predicted homozygotic PER3 genotypes (PER3(5/5) vs. PER3(4/4)).
• Individuals with the PER3(5/5) genotype reported stronger morning preferences.
• The need for an alarm clock was the only item discriminating between all three genotypes.
• Age correlated with non-genotype-predictive items, not genotype-predictive ones.

Conclusions:

• Specific items of the HO questionnaire can predict PER3 genotypes associated with diurnal preference.
• Findings suggest a genetic component influencing diurnal preference, potentially modulated by age.
• This research aids in developing chronotype scales for studying biological parameters.