A functional polymorphism in the HTR2C gene associated with stress responses: a validation study.

Area of Science:

• Neurogenetics
• Endocrinology
• Psychophysiology

Background:

• A specific gene variant (SNP rs6318) on the X-chromosome's HTR2C gene was previously linked to stress response.
• The hypothalamic-pituitary-adrenal (HPA) axis regulates the body's reaction to stress, involving cortisol release.

Purpose of the Study:

• To validate the association between the HTR2C gene variant (rs6318) and cortisol response to acute stress.
• To extend previous findings to a new, independent sample, including both males and females.

Main Methods:

• Recruitment of 60 adult participants for a second, independent study.
• Administration of a laboratory-based emotional stress recall task.
• Measurement of cortisol levels and calculation of cortisol response and area under the curve.

Main Results:

• Homozygosity for the Ser23C allele of rs6318 was significantly associated with a greater average cortisol response (p=0.007) and cortisol area under the curve (p=0.021) compared to Cys23 G allele carriers.
• The cortisol increase from baseline was approximately double in Ser23C homozygotes versus Cys23 G carriers.
• These results were consistent with prior findings and included female participants.

Conclusions:

• The association between the HTR2C gene variant (rs6318) and cortisol reactivity to acute stress is validated in an independent sample.
• This genetic variation influences the physiological stress response, as measured by cortisol levels.
• The findings confirm the role of HTR2C in modulating the HPA axis response to stressors.