The Process of How COMT
Genetic Variants Provide the
Foundations of Human
Behavior
Booklet on behavioral predispositions for students
seeking to improve study habits and exam grades
By Michael Buzzell
Audience and Purpose
Are you unsatisfied with your exam grades even though you study well? Or maybe
you cram all of your studying in the night before exams. These two extreme
behavioral approaches to the goal of championing an exam may be caused by gene
variants. You could have been born as a poor test taker or a chronic procrastinator;
however, these behavioral issues can be helped.
The purpose of this document is to describe the process of how two COMT gene
variants cause different behavioral predispositions in humans. Attention will be
given to the pros and cons of the two behavioral predispositions resulting from the
COMT gene. Use this information to talk to a medical professional about possible
strategies and medication that may improve your performance in school.
Introduction
All humans differ from one another based on physical appearance, susceptibility to
disease, and behavioral predispositions. These differences are evidenced by the
unique sequences of DNA in every individual. Each DNA sequence functions as a
blueprint to build a person with all the necessary vital components. All of the human
DNA blueprints contain 99.9% of the same information, but the small differences in
the DNA code are significant enough to differentiate every human being.
The COMT gene is a small portion of a human DNA sequence that provides
instructions on how to build the COMT enzyme. The COMT enzyme, a molecule that
changes the shape of dopamine, is a critically important protein that regulates a
motivational chemical (dopamine). With this in consideration, it is interesting to
identify that the DNA blueprint instructions for building the COMT enzyme are not
the same in all humans. These different instructions build a diverse collection of
COMT enzymes predisposing humans to different behavioral traits.
The Contents of the COMT Gene
The content of the COMT gene is made up of 20 million DNA base pairs:
programming units of DNA like the 1s and 0s in computer binary code. These base
pairs are almost exactly the same in all humans; however, there is one single base
pair in the COMT gene that commonly differs among individuals. This single base
pair out of the 20 million base pairs in the gene may determine whether an
individual lives a healthy life or develops schizophrenia. When a single base pair
determines a specific trait of an individual, it is called a Single-Nucleotide
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Polymorphism (SNP). In the COMT gene, this common SNP consists of two variants,
also known as alleles, of the DNA blueprint for the COMT enzyme.
Figure 1. SNP present between two strands of
DNA. Only one base pair is different, the rest are
the same across the DNA sequence. There is
only one common SNP in the 20 million base
pairs of the COMT gene and it has a significant
impact on behavioral predispositions.
Two slightly different COMT enzymes result
from the two different sets of information
on each allele. These two alleles are called
the Val and Met allele. Each parent donates
one Val or Met allele to his or her offspring. This results in half of the population
receiving both variants of the COMT gene (Val/Met), while the other half receives
only one type of the COMT gene (Val/Val or Met/Met). The half of population that
only receives one type of the COMT gene is the most interesting because there are
clear behavioral advantages and disadvantages of possessing the Val or Met alleles.
Individuals that receive a Val allele from both parents are classified as Warriors,
while the individuals that receive a Met allele from both parents classified as
Worriers (Stein, 745). These classifications arise from the behavioral implications
these alleles have on humans.
The Role of the COMT Enzyme in Regulating Dopamine to
Influence Behavior
Dopamine is the most important chemical in the brain when approaching tasks
involving attention and memory, but the COMT enzyme is responsible for regulating
the amount of dopamine available in the brain because it is only effective in
moderate amounts.
Not enough dopamine in the brain
 Depression
 Attention Deficiency
 Greater risk of developing
Parkinson’s disease
Too much dopamine in the brain
 Anxiety
 Impulsive decision-making
 Greater risk of developing
Schizophrenia and Bipolar
disorders
Because dopamine levels in the brain are so critical to human behavior, the
capability of the COMT enzyme is essential to one’s mental health.
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The effect of dopamine is activated in the brain’s nerve cells. Dopamine is a
neurotransmitter that is sent from a delivery end of a nerve to a receiving end of
another nerve across a synaptic gap.
Figure 2. Neurotransmitters flowing from the delivery end
of a nerve (axon) to the receiving end (dendrite) of another
nerve. The space between the nerves is the synaptic gap
The COMT enzyme can degrade dopamine before it
travels across a synaptic gap to activate another nerve.
The enzyme changes the chemical structure of
dopamine so that it no longer fits in a nerve receptor.
The COMT enzyme built from the Warrior allele is
more actively involved in the degradation of
Dopamine than the enzyme constructed from the Worrier allele. Warrior enzymes
can degrade dopamine up to four times the rate of their Worrier counterparts
(Morrow, 468). Individuals with the Warrior COMT gene generally have lower levels
of dopamine than those who possess the Worrier gene due to the disparity between
the catabolic rates of the COMT enzymes. Overall, COMT gene alleles predestine
individuals to certain behavioral traits based on the amount of dopamine it allows in
the brain.
There are advantages and disadvantages of both the Warrior and Worrier genes.
When one experiences aversive stimuli, such as looming exam or criticism from an
authority, dopamine levels naturally increase in the brain. A Warrior will have a
genetic advantage in this case because he or she possesses COMT enzymes that can
work efficiently to restore moderate dopamine levels for productive mental
processing. Conversely, Worriers will experience high dopamine levels for a longer
period of time because their COMT enzymes do not degrade dopamine very quickly.
As a result, Worriers may experience anxiety and perform poorly under intense
stress, hence, the term Worrier.
In spite of the struggles Worriers experience under stress, they perform better
during memory and attention tasks when aversive stimuli is not present. In
contrast, Warriors are pre-disposed to be unmotivated because they operate on
relatively low levels of dopamine. Warriors must wait to experience aversive stimuli
again to perform attention-based tasks with ideal efficiency.
Warrior COMT gene
Performs well
Performs poorly
when stress
when stress
stimulus is present
stimulus is NOT
present (dopamine
levels are too low)
Worrier COMT gene
Performs well
Performs poorly
when stress
when stress
stimulus is NOT
stimulus is present
present
(dopamine levels
are too high)
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Conclusion
All in all, the COMT gene inherited by an individual works to influence significant
behavioral predispositions. Warriors are genetically prepared to handle stress more
than others but are susceptible to procrastinate work habits. Worriers are
genetically superior when approaching daily attention tasks, but they may suffer
from anxiety under competition and pressure. People can map their own genomes
to discover what variation of the COMT gene they possess and apply that knowledge
to their personal study habits. If students discover they possess the Worrier gene,
then they should approach medical professionals with concerns about anxiety
before an exam or other stressful assignments.
On the other hand, students that are Warriors may seek help from a medical
professional for motivational supplements. If doctors suspect a patient has
Attention-Deficit Disorder, then they can confirm their conclusion by reading about
that patient’s Warrior genetic composition before prescribing a dopamine stimulant.
Don’t let the composition of the COMT gene limit your academic success. Break the
mold of your behavioral predispositions with the help of medical professionals.
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Works Cited
Morrow, Ben. "Association of Codon 108/158 Catechol-O-methyltransferase Gene
Polymorphism with the Psychiatric Manifestations of Velo-cardio-facial
Syndrome." National Center for Biotechnology Information. American Journal of
Medical Genetics, 20 Sept. 1996. Web. 26 July 2014.
Stein, DJ. "Warriors versus Worriers: The Role of COMT Gene Variants." CNS Spectrums 10
(2006): 745-48. National Center for Biotechnology Information. 11 Oct. 2006. Web. 26
July 2014.
Figure 1. "Dna-SNP" by David Hall (Gringer) - Own work. Licensed under Creative
Commons Attribution 2.5 via Wikimedia Commons http://commons.wikimedia.org/wiki/File:Dna-SNP.svg#mediaviewer/File:DnaSNP.svg
Figure 2. "Synapse Illustration" by Synapse_Illustration2_tweaked.svg:
Nretsderivative work: Looie496 (talk) - Synapse_Illustration2_tweaked.svg.
Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia
Commons http://commons.wikimedia.org/wiki/File:Synapse_Illustration_unlabeled.svg#medi
aviewer/File:Synapse_Illustration_unlabeled.svg
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