Serotonin (5-Hydroxytryptamine or 5-HT), as some of us may know, is a neurotransmitter that is involved in modulation of moods such as anger. The level of re-uptake of serotonin by the presynaptic neuron is crucial and abnormal functioning of the serotonin transporter has been implicated in different neurological diseases. The human 5-HT transporter (5-HTT) gene transcription is modulated by a common polymorphism in the upstream regulatory region and the short variant of the polymorphism reduces 5-HTT transcription and hence reduces 5-HT uptake by lymphoblasts. In this paper, the authors (Lesch et. al (1996)) report association studies demonstrating that the presence of the short variant pre-disposes the individual towards anxiety related personality traits.
Neuroticism scores (seperated into eight groups) and percentages of subjects
from L(n=163) and S(n=342)groups in each of the eight T-score groups.
Notice that the S percentage is higher than L percentagein all T-score groups
above 54 (Lesch et. al (1996))
Lesch, K., Bengel, D., Heils, A., Sabol, S., Greenberg, B., Petri, S., Benjamin, J., Muller, C., Hamer, D., & Murphy, D. (1996). Association of Anxiety-Related Traits with a Polymorphism in the Serotonin Transporter Gene Regulatory Region Science, 274 (5292), 1527-1531 DOI: 10.1126/science.274.5292.1527