PER3 Gene

What is the PER3 gene?

PER3 encodes period circadian regulator 3, a protein involved in circadian clock. It belongs to the Circadian Rhythm category and is part of the Neurological & Sleep biological cluster. PER3 encodes a circadian clock component with a variable number tandem repeat (VNTR) polymorphism affecting sleep phenotypes. The 5-repeat allele is associated with morning preference while the 4-repeat allele associates with delayed sleep phase.

Biological role and pathway

PER3 is involved in the circadian clock pathway, which plays a central role in regulating physiological processes relevant to immune defence, cellular energy, and systemic homeostasis. Genes within the Neurological & Sleep cluster work together to maintain balanced function across interconnected biological systems.

Variants in genes within this pathway may influence an individual's predisposition to altered function in these systems — particularly under conditions of physiological stress such as viral infection or prolonged illness.

Known genetic variants

The following variants (SNPs) in the PER3 gene have been studied in relation to circadian rhythm and chronic illness. Each variant represents a single nucleotide position where individuals may carry different alleles.

• rs57875989— PER3 variant
• rs228697— PER3 variant
• rs10462021— PER3 variant

Conditions studied in relation to PER3

Research into PER3 variants has explored associations with the following conditions. These are areas of scientific investigation and do not imply that PER3 causes or treats any condition.

Genetic insights from DNA data

Consumer DNA files from 23andMe, AncestryDNA, and MyHeritage contain raw SNP data. When you upload your file to ChronicDNA, the analysis engine checks your genotype against a curated panel of 80+ genes selected for their relevance to Long COVID, ME/CFS, and connected biological pathways - some of which may include PER3 and related genes in the neurological & sleep pathway.

The report is educational - it explains which variants you carry, what the research says about them, and how they fit into the biological pathways most relevant to chronic illness. Results are presented in plain English with appropriate scientific context, no medical jargon, no scare tactics. All results should be discussed with a qualified healthcare provider.

Related genes in the Neurological & Sleep pathway

PER3 does not act in isolation. The following genes are functionally related and may be analysed together for a more complete picture of your genetic predispositions.

Frequently asked questions