Introduction
Brunner syndrome is a recessive X-linked disorder characterized by impulsive aggressiveness and mild mental retardation associated with MAOA deficiency. According to Brunner, it is a rare genetic disorder with a mutation in the MAOA gene (monoamine oxidase A gene). It is characterized by lower than average IQ (typically about 85), is a problematic impulsive behavior (such as arson, hypersexuality and violence), is also a sleep disorders and mood swings. Brunner syndrome was first discover by Hens G. Brunner; his findings has been used to argue genetics, and the behavior can cause criminal activity. Evidence supporting the genetic defense stems from both Brunner’s findings and a series of studies on mice have proven correlation
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between MAO-A deficiency and aggression. It is often contended that individuals cannot be held accountable for their genes, and as a result, should not be held responsible for their dispositions and resulting actions (Caspi, 2002). History and Clinical Features In 1993 Brunner Syndrome was described by H.G.
Brunner and his colleagues, and upon the discovery of a particular genetic defect in male members of a large Dutch family. In this large Dutch kindred, Brunner et al. (1993) identified a novel form of X-linked nondysmorphic mild mental retardation, and he found that all of the male family members with this defect reacted aggressively when angry, fearful, and frustrated. All the affected males in the family showed characteristic abnormal behavior, in particular aggressive, and sometimes violent behavior. These males in the family displayed mild impairment of cognitive functions and some types of abnormal impulsive behavior which includes arson, attempted rape, and exhibitionism. Even attempted suicide was reported in a single case. The defect discovered was later found to be a mutation in the gene that codes for monoamine oxidase A (MAOA gene). Brunner showed that in the affected males there was a mutation in the gene for the enzyme monoamine oxidase A (MAOA). The enzyme deactivates the hormones and neurotransmitters epinephrine and norepinephrine, more commonly known as noradrenaline and adrenaline. At this time, Brunner said that an "MAO-A deficiency is associated with a recognizable behavioral phenotype that included disturbed regulation of impulsive aggression. The transmission pattern of Brunner syndrome in the families reported was consistent with X-linked recessive inheritance. A man with Brunner syndrome is what expert psychiatrists refer to as “a bad guy.”
Signs and Symptoms of Brunner Syndrome
Aggression may be associated with other symptoms that are determined by the underlying disorder or illness. Ailments that influence behavior often also have psychological, cognitive, and physical symptoms. Some additional signs and symptoms may include:
• Aggressive
behavior • Violent behavior • Mental retardation • Moodiness • Depression • Threatening behavior • Trauma, such as bone deformity. • Alterations in mental status. • Personality fluctuations • Social withdrawal • Impaired judgment and decision making Aggression and Locations of MAOA Proteins The MAOA protein is positioned at the outer mitochondrial membrane in neurons and astrocytes in the central nervous system (i.e. brain and spinal cord) to control both monoamine neurotransmitter availability for sequestration and the following extrasynaptic inactivation after release (Hebebrand & Klug, 1995). Outside the central nervous system, MAOA proteins are also found in the heart, liver, duodenum, blood vessels and kidney. MAOA protein is also a mitochondrial enzyme in charge of catalyzing the oxidative deamination of biogenic and xenobiotic amines, along with essential functions in the metabolism of neuroactive and vasoactive amines in the central nervous system and peripheral tissues. Biogenic amines like 5-hydroxytryptamine (5-HT), norepinephrine and epinephrine have higher prioritization for oxidation by the MAOA protein (Brunner et al,. 1993). Norepinephrine Epinephrine Both epinephrine and norepinephrine are part of the body’s “fight or flight” response (80% of the hormones released are epinephrine and 20% norepinephrine). This is the body’s response to dangerous or unexpected situations. The effect is the dilatation of the blood vessels to the muscles, the stopping of digestion and the increase in heart and breathing rate. This prepares the body for persistent muscles contraction in life-threatening situations. In this hyper-excitable state there is increased male aggression (Hollander, 2000). Causes of Brunner Syndrome Brunner syndrome is caused by a monoamine oxidase A (MAOA) deficiency, which leads to an excess of monoamines in the brain, such as serotonin, dopamine, and norepinephrine (DeSmedt, 2002). Some other causes includes: • Genetic: which the behavior can be passed down by a family member. • The Brain-Behavior Connection: The frontal lobes, which is associated with functions such as impulse controls. • Modeling: When children grow up in a home where aggression is a common expression of distress. • Other Disorders: previously listed disorders; these can be an additional conditions which can lead to aggression including brain tumors and closed head injuries. Some of these disorders may include bipolar disorder, conduct disorder, and ADHD. Treatment for Brunner Syndrome To work through Brunner Syndrome (aggressive) behavior, you need to identify its underlying causes. Impulsive behavior and aggression are present in a broad range of disorders. Although there have been some attempts in developing specific anti-aggression drugs or the “serenic” class of medications. Here are some of the treatments that are currently used: • Therapy • Medication • Impulse control • Increasing your dopamine level (a compound present in the body as a neurotransmitter). • Positive parent and child Relationships (don’t neglect your child). It may help to talk to someone about experiences that make you feel aggressive. In some cases, you can learn how to avoid frustrating situations by making changes to your lifestyle or career. You can also develop strategies for coping with frustrating situations. For example, you can learn how to communicate more openly and honestly, without becoming aggressive. Many classes of medications have been used to treat Brunner syndrome. These include the selective serotonin reuptake inhibitors (SSRIs), 5-HT receptor agonists and antagonists, lithium, anticonvulsants, typical as well as atypical neuroleptics, beta blockers, alpha antagonists such as clonidine, opiate antagonists such as naltrexone, and dopamine agonists such as bupropion and amphetamines (Nock, 2003). Your doctor may recommend psychotherapy to help treat aggressive behavior. For example, cognitive behavioral therapy (CBT) can help you learn how to control your behavior. It can help you develop coping mechanisms. It can also help you understand the consequences of your actions. Talk therapy is another option. It can help you understand the causes of your aggression. It can also help you work through negative feelings. Experiment by Hens Brunner Participants 5 Males from the family in the Netherlands, all of whom have the same genetic condition, which was later called Brunner Syndrome. Two carrier females and one non-carrier females were used as a control and compared with 3 clinically affected males. Females are not affected by the condition, although they can carry the condition in their genes, but they do not exhibit any symptoms. Results According to Hens Brunner, all the males that were tested acted aggressively when angry, fearful, or frustrated. A base change in the DNA structure was identified in all 5 males. This in turn resulted in flawed monoamine metabolism, which is linked with a deficit of the enzyme monoamine oxidase A (MAOA). The reason only males are affected is because it is specifically the single X chromosome which is responsible for the production of MAOA. These data were considered consistent with a primary defect in the structural gene for MAOA. Conclusions Brunner concluded that it is likely that the defect in the gene which causes flawed serotonin metabolism is the cause of the mental retardation and thus the aggressive behavior exhibited in the males. The MAOA deficiency accounts for their inability to regulate their aggression. It is important to note that not all the males in the family were afflicted with the inability to control their aggression, even if they suffered mental retardation. Although it could be argued that this study is questionable as there is a complete lack of other variables studied, given that there were males who did not exhibit aggressive behavior. While the study of behavioral genetics remains a controversial topic, with disagreement not just over the science itself, but even more so about the therapeutic, societal and legal implications, I will conclude that Brunner Syndrome is a disease that can be easily cured with some medications and some therapy.
In Holland, male members of a certain family were found to be prone to violent outbursts; one male, criticized by his employer, attempted to run him over with a car - another raped his sister and was sent to a mental hospital - a third coerced his sister into undressing by threatening her with a knife. Such men display retarded motor development, difficulties in task planning, and awkward sexual behavior. (1). Recently, researchers claimed to have found the basis of such aggressive behavior to genetic sources - specifically, a deficiency in the MAOA gene of these males (2).
Stochholm, K., A. Bojesen, A. S. Jensen, S. Juul, and C. H. Gravholt. "Criminality in Men with Klinefelter's Syndrome and XYY Syndrome: A Cohort Study." BMJ Open 2.1 (2012): E000650. Print.
Volkows, N. D., & Muenke, M. (2012). Human Genetics. The genetics of addiction, Vol 131(6), 773-777. Retrieved from http://dx.doi.org/10.1007/s00439-012-1173-3
... variant of MAOA that exhibit deficiencies is the MAOA-L. MAOA-L predisposes a person to psychopathic traits. However, there has to be something that triggers that gene. Moreover, males are more likely to have it than females, which would explain why psychopaths are mostly male.
This book is partly a psychiatric textbook and partly a self-help book. It reviews the biology, psychology, and genetics of different personality disorders, such as narcissism, paranoia, antisocialism, and obsessive compulsive. The author, Stuart C. Yudofsky MD, graduated with an MD from Baylor College of Medicine. His practice focuses in two areas: psycho-pharmacology and neuropsychiatry. He is the D.C. of the Menninger Department of Psychiatry and Behavioral Sciences of Baylor College of Medicine and the chairman of the Psychiatry Department of The Methodist Hospital. The publisher, American Psychiatric Pub., is a global publisher of books, journals, and multimedia on psychiatry, mental health and behavioral science.
It is also crucial to consider the genetic makeup of these killers when trying to decipher their motives. New research shows a potential link between a strand of genes and aggression and violence (Bradley-Hagerty). The MAO-A gene or (monoamine oxidase A) has been researched extensively. The gene is often referred to as the “warrior gene” (Bradley-Hagerty). The function of this gene is to regulate serotonin in the brain. However, there are different variations of the gene, one of which is believed to prevent the brain from feeling the relaxing effects of the serotonin (Bradley- Hagerty). Without these calming effects, the person with this version of the gene is genetically predisposed to fits of rage; fits of rage that could potentially lead to murder over and over again.
There are many people with this illness that is quite hard to diagnose. Unfortunately, these people are seeking a little kindness and attention, while, in the meantime, they are at possible risk to themselves. Most of the studies show that the cause of onset of this disorder begins with the patient’s childhood and being abused or rejected.
To think how far we have come with medicine and technology is astounding. Looking into the biological model of abnormalities we learn that the focus is to connect a medical prospective to the variations in abnormal behavior. The text uses the case of Philip Berman, a person who exhibits a wide range of emotion when triggered with certain topics. In this case researchers are looking to find a glitch between his body chemistry and his behavior. The question here is: Can there be a connection between imperfect organisms within the body which in turn display abnormal behavior? We learn from the text that the brain has many parts that are designed to specific duties. If one of the nerves or cells is faulty, can it somehow be tied to the way a person acts? The answer is yes. We know that abnormal behavior is not just that of a mental disorder, and we know that certain chromosomal disorders have been proven to cause abnormalities within the human body. In Philip’s case, it is not necessarily a behavior that we know could be caused by a glitch in the system. We learned many facts about his life that can play a role in the way he carries himself. If we were looking into his genetic inheritance we might ask questions like the genetic makeup of the family history (i.e. has there been a history of mental disorder in the family?). Was Philip used to being an only child for so
The million-dollar question that circulates in the minds of many which clearly led to continuous research by neuroscientists. Jim Fallon on a Ted Talk dated July 16, 2009 openly expressed his discovery that damage to the ventromedial prefrontal cortex, which deals with emotional responses and decision making can ultimately lead to changes to an individual’s personality marked by poor judgement and impulsive choices. Therefore, these functions are similar to a light switch which can either be turned on or off and as explained by Mr. Fallon it is increasingly difficult to cure such damage to the brain. Interestingly, he went further to single out a particular gene known as MAOA which is considered to be a high-risk gene. Jim Fallon made that point to say that mutation of that gene can result in problematic behavior which is the case of many serial killers, therefor there is sufficient evidence to prove nature as a factor (Fallon,
In all of these possibilities--instinct, heredity, hormones, or brain dysfunction--the aggression occurs without apparent provocation from the environment (although there is almost always a "target"). According to some of these theories, the need or urge to be aggressive is boiling within each of us and seeks opportunities to express itself. There is also clear evidence that alcohol consumption and hotter temperatures release aggression, but no one thinks there is something in alcohol or heat that generates meanness. The socialization process, i.e. becoming a mature person, involves taming these destructive, savage, self-serving urges that probably helped us humans survive one million years ago but threatens our survival today.
Subsequently, since discovering that both biological and sociological aspects both play a part in human behavior, studies began to formulate to see whether nature or nurture held a stronger influence. Two of the main studies done were the family and twin studies. Family studies are defined as “studies that examine the clustering of criminality in a given family” (Schram, P. J., & Tibbetts, S. G.). One of the families that was studied was the Kallikak family by H. H. Goddard. Through this study they found criminality is more common in some Neurotransmitters are chemicals in the brain and body that help transmit electric signals from one neuron to other neurons in the body.
Some factors that are explored in studies involves the genetics in a person, how parents treat their children, influences peers have and the situations that a person may experience throughout their childhood and adult life. There is a possible connection between the feelings of anxiety, aggression and fear with a genetic makeup in a person’s body (Huff, 2004). Research has even shown that if an individual was abuse, whether physical or verbally they are at risk for developing a personality disorder as well (Huff, 2004). Another interesting study conducted by Robert Krueger, PhD, exploring the influences that can contribute to the development of a personality disorder, looks at studying personality traits within identical twins who did not grow up together. In the study, it appeared that genetics contributed more to a person personality trait then the environment they were in. Krueger opinion was that “The predominant reason normal and abnormal personality are linked to each other is because they are linked to the same underlying genetic mechanisms” (Huff,
...dgkinson C, Raymont V, Ferrier C, et al. Prefrontal cortex lesions and MAO-A modulate aggression in penetrating traumatic brain injury. Neurology. 76(12):1038-45 (2011).Van Erp AM, Miczek KA. Aggressive behavior, increased accumbal dopamine, and decreased cortical serotonin in rats. Journal of Neuroscience. 20(24):9320-5(2000).Vrontou E, Nilsen SP, Demir E, Kravitz EA, Dickson BJ. fruitless regulates aggression and dominance in Drosophila. Nature Neuroscience 9, 1469 - 1471 (2006).)
...fers low levels of monoamine oxidase enzyme, thus predisposing the individual to criminal behaviour (Lee).
can lead to long term mental health issues, often times worse than aggression. In early childhood,