Validation and TaqMan Conversion of a Molecular Chronotype Assessment Approach.

Area of Science:

• Genetics
• Chronobiology
• Molecular Biology

Background:

• Chronotype, an individual's daily activity timing, is influenced by genetic factors.
• Previous research identified 35 genetic variants associated with chronotype.
• Developing a reliable molecular tool for chronotype assessment is desirable.

Purpose of the Study:

• To develop a TaqMan genotyping card for molecular chronotype assessment.
• To validate the performance of a predictive panel of genetic variants for chronotype.
• To assess the utility of the genotyping card in diverse populations.

Main Methods:

• Developed a TaqMan assay for 33 out of 35 chronotype-predictive genetic variants.
• Genetically characterized 292 individuals using the TaqMan card.
• Assessed phenotypical chronotype using the Morningness-Eveningness Questionnaire and Munich Chronotype Questionnaire.
• Validated the predictive panel using logistic and linear regression models on different cohorts, including the Estonian Biobank (25,986 individuals).

Main Results:

• Successfully developed a TaqMan genotyping card for 33 genetic variants.
• The logistic regression model showed 72% predictive value for extreme chronotypes (morning/evening).
• Predictive performance decreased significantly (45%) when including intermediate chronotypes.
• No significant genotype-chronotype associations were found in the large Estonian Biobank sample.

Conclusions:

• The developed TaqMan genotyping card is a promising molecular tool for chronotype assessment, particularly for extreme chronotypes.
• Its predictive accuracy is limited when intermediate chronotypes are included.
• Further studies are needed to evaluate the card's performance in diverse populations.