Genes determine almost all of our physical and nonphysical features. We inherit all of our genes from our parents, but they’re not always for the better. Some are bad, and we would have been better off without them.
People have ended up with severe and life-threatening conditions simply due to inheriting the wrong genes. We’re not talking about ailments like Down syndrome; we mean unbelievable conditions you would have never imagined could be linked to your genes.
Variants of the MAOA gene and the cadherin 13 (CDH13) gene are referred to as “warrior genes” because they are linked with violent behavior. A 2014 study by Finnish researchers revealed that criminals with the genes were responsible for between five and ten percent of all crimes committed in Finland.
If that wasn’t scary enough, people with these warrior genes are 13 times more likely to become repeat offenders than those without the genes. The 900 convicts involved in the study were responsible for a total of 1,154 murders, attempted murders, manslaughters, and violent assaults.
However, having the warrior genes by no means guarantees that one will become violent. In fact, researchers noted that most of the people with the genes will never take to crime. They also added that the effects of the genes can be suppressed with proper upbringing. Some researchers think the MAOA and CDH13 genes cannot be blamed for violent acts committed by people, since half of the Finnish population probably has them.
Scientists have discovered a link between depression, suicide, and the RGS2 gene. A 2011 study led by John Mann of the New York State Psychiatric Institute revealed that one variant of the RGS2 gene could cause depression, while another variant could make people more prone to suicide.
Researchers believe the RGS2 gene could explain why generations of the same family sometimes commit suicide. There are suspicions that the suicide variant could be present in the family of famous writer Ernest Hemingway (pictured center above with his family), who committed suicide in 1961 after attempting suicide earlier the same year. Hemingway’s father also committed suicide in 1928, and so did Hemingway’s granddaughter and two of his siblings.
The study involved 412 people suffering from serious depression. Of that group, 154 had attempted suicide sometime in the past. The study revealed that 43 percent of the 154 people had aggressively suicidal variants of the RGS2, while one fifth had copies of a less suicidal variant.
While Mann agreed that detection of the gene could be used an in indicator of someone’s risk of suicide, he added that the study was inconclusive and mentioned that further research was required to reach a definite conclusion.
Researchers have discovered that parents could transfer the effects of traumatic experiences they’ve suffered to their offspring through their genes. This has been observed in descendants of slaves, survivors of the Holocaust, and veterans of the Vietnam War, who have genetically transferred post-traumatic stress disorder (PTSD) to their offspring.
The research was led by Dr. Rachel Yehuda of the Icahn School of Medicine at Mount Sinai in Manhattan. Dr. Yehuda explained that when people experience a deeply traumatic event, it can actually alter their genes. These changes are passed down to descendants.
A Jew herself, Dr. Yehuda sampled several Jewish neighbors who were descendants of the Holocaust survivors as part of the study. She discovered their hormones closely resembled those of PTSD-afflicted veterans of the Vietnam war. Also, the amygdala—the part of the brain responsible for processing emotions—was overly active like those of Vietnam veterans.
Descendants of black slaves also suffer from similar problems. In fact, sociologist Dr. Joy DeGruy even coined the term “Post Traumatic Slave Disorder” to refer to the effects of slavery in the genes of the descendants of black slaves.
The DRD4 gene is responsible for regulating the dopamine levels in our bodies. Dopamine is a chemical released in the brain and is associated with things like motivation and sexual satisfaction. Our bodies consider it a sort of reward, which is why it is usually released when we engage in fun behaviors like gambling, drinking, and sex.
A 2010 study led by Justin Garcia of Binghamton University, New York, has revealed that a variant of the DRD4 gene could actually make people more prone to cheating on their partners. Garcia and his team reached this conclusion after studying 181 young people. The researchers discovered that people with the gene were more likely to engage in infidelity and one-night stands.
However, Garcia says that unfaithful partners should not consider the presence of the gene variant an excuse for their philandering behavior. He also added that having this variant of the DRD4 gene does not guarantee that a person will cheat.
Series of studies on both humans and animals indicate that females live longer than males. In humans, the life expectancy of men and women differs by five to six years on average, with the women lasting longer. Research has revealed that this is caused by genes referred to as the “Mother’s Curse.”
The Mother’s Curse is called such it is in the mitochondrial DNA, which comes from the mother. Both sexes actually inherit the genes, but they are unfavorable to males, since they make them age faster and die earlier than women. However, the genes have no effects on females, who will pass them to their own offspring.
In 2018, researchers revealed the discovery of three genes linked to chronic back pain after a study involving 29,000 suffering from the condition. The group was part of a larger set of 158,000 Europeans involved in the study.
One is the SOX5 gene, which is the most dominant of the three genes. It is actively involved in our embryonic development. Interestingly, lab rats involved in an earlier study were left with skeletal defects after the gene was deactivated in their bodies.
As for the two other genes, one is involved in the development of our spinal cord, while the other is linked to intervertebral disc herniation (aka “slipped disc”), a medical condition that can cause back pain. The intervertebral discs are the principal joints between the vertebrae of the spinal column.
A team of researchers led by Rebecca M. Todd of the University of British Columbia have discovered that being pessimistic or just having negative thoughts could all be in the genes. The gene responsible is the ADRA2B gene, which is one of the many genes responsible for our emotions.
However, the ADRA2B gene must be missing some amino acids to cause the pessimistic behavior. People with the missing amino acids are more likely to notice negative events more readily than they observe positive or neutral events. For instance, they will notice the criminal-like character in a street faster than they notice a group of playful children.
The pessimistic ADRA2B gene was discovered during a study involving 200 people. The group were shown two words in quick succession and asked to pay attention to the second word. Most people saw the first word but often had problems recognizing the second word.
However, people with the pessimistic ADRA2B gene often recognized the second word whenever it was a more emotion-evoking word, like “rape” or “orgasm.” Some researchers, like Ahmad R. Hariri of Duke University, believe the existence of a pessimistic gene is a fallacy. He says pessimistic behavior is not linked to a single gene but several.
The Vikings suffered from severe intestinal worm infestations. This is evident in poop samples recovered from ancient Viking latrines in modern Denmark. The worms often secreted dangerous enzymes called proteases, which can damage crucial internal organs, including the liver and lungs.
The immune systems of the Vikings prevented any damage due to a mutation in the alpha-1-antitrypsin (A1AT) gene. The regular A1AT gene protects our organs from proteases produced by our immune system. However, the mutated version also protects the Vikings from proteases secreted by the worms.
Without the regular or mutated A1AT genes, proteases would damage the lungs, causing health conditions like chronic obstructive pulmonary disease (COPD) and emphysema. However, researchers from the Liverpool School of Tropical Medicine have observed that many Viking descendants—who number over 300 million today—suffer from lung problems like emphysema.
Research revealed that the descendants of the Vikings are at a higher risk of lung problems because the mutated A1AT genes they inherited from their ancestors do not offer the same amount of protection against the proteases created by the immune system. Of course, the risk of a Viking descendant developing lung problems becomes higher if the person is a smoker.
A study involving 113,006 people revealed the existence of seven genes that could cause insomnia. Interestingly, some of these genes were already known to cause other unfavorable conditions, like depression, anxiety disorders, and restless legs syndrome (RLS), which can all lead to insomnia. It’s little wonder that people with insomnia often suffer from one or more of these conditions at the same time.
One of the genes is the MEIS1 gene, which is also associated with RLS and periodic limb movements of sleep (PLMS). RLS sufferers often have the urge to move their legs, leading to sleeplessness and fatigue. PLMS is similar, except that sufferers move their limbs in their sleep without waking. However, they are often left tired the next day.
It is commonly held that women talk more than men. This claim is backed by research, which shows that women say around 20,000 words per day, while men say just 7,000. Women also pick up languages faster than men and learn to speak and read younger.
A study conducted by the University of Maryland School of Medicine indicates that this could all be in the genes. The researchers pinpointed the FOXP2 gene, which is one of the many genes responsible for speech in humans. The FOXP2 gene secretes a special protein in the brain. Researchers have linked that protein to the generally more talkative nature of women.
The study involved a small sample group of just ten children: five male and five female. A check on their brains revealed girls had 30 percent more of the protein made by the gene than boys. However, while the researchers agree that their study is a good start, they consider it inconclusive since it involved a small sample group.