Tag Archives | Genetics

Is There Really A Psychopath Gene?

A single gene has been linked with being a psychopath — and it’s very controversial – reports Tanya Lewis at Business Insider:

As of yet, no single factor can explain what causes people to behave in ways labeled psychopathic. But research suggests our genes may play a role.

Edward Hopper's The House by the Railroad, used as inspiration for the look of the Bates house in the movie "Psycho."

Edward Hopper’s The House by the Railroad, used as inspiration for the look of the Bates house in the movie “Psycho.”

 

One gene in particular is linked with an increased risk of violent or aggressive behavior, studies have found.

Known as MAOA (monoamine oxidase A), this “warrior gene” controls the production of a protein that breaks down brain-signaling chemicals like dopamine, noradrenalin, and serotonin, which all influence mood.

But the idea of a “psychopath” gene remains controversial.

A gene for psychopathy?

People with a variant of the gene, called MAOA-L, produce less of the protein that breaks down these signaling chemicals, which in turn causes them to build up.

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Rape Culture…or Rape DNA?

Michael Dales (CC BY-NC 2.0)

Michael Dales (CC BY-NC 2.0)

Jim Goad writes at Taki’s Magazine:

The April edition of International Journal of Epidemiology contains an article called “Sexual offending runs in families: A 37-year nationwide study.” A summary of the article runs as follows:

Close relatives of men convicted of sexual offenses commit similar offenses themselves more frequently than comparison subjects. This is due to genetic factors rather than shared family environment….

The study scrutinized the records of all 20,000+ convicted sex offenders in Sweden from 1973-2009. It concluded that compared to males in the general population, brothers of convicted sex offenders are roughly five times more likely to also commit sex crimes. Sons of convicted sex offenders are about four times as likely to follow in daddy’s skeevy footsteps. Researchers reportedly teased out variables such as family environment to reach their conclusions. For example, half-brothers raised under the same roof proved far less likely to both be sexual predators than full blood brothers raised under the same roof.

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Autism Awareness Day: Newly Discovered Genetic Variant Causes Autism

Today, as most of you are probably aware, is World Autism Awareness Day. Fittingly, John Hopkins University has recently identified a new genetic variant that causes autism. Researchers used a novel approach that targeted 13 families severely afflicted with autism, specifically families with more than one woman on the autism spectrum. “For reasons that are not understood, girls are far less likely than boys to have autism, but when girls do have the condition, their symptoms tend to be severe.” [Read more: New Theory May Explain the Symptoms of Autism]

According to Aravinda Chakravarti, Ph.D., a professor in the Johns Hopkins University School of Medicine’s McKusick-Nathans Institute of Genetic Medicine, “In genetics, we all believe that you have to sequence endlessly before you can find anything. I think whom you sequence is as important — if not more so — than how many people are sequenced.” 

Chakravarti hypothesized that, because autism in girls is so rare, those afflicted must carry some type of genetic variant.… Read the rest

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Sleep Paralysis Linked to Genetics, Anxiety & Stressful Events

Henry Fuseli's "The Nightmare" may have been inspired by the chest-crushing sensation and hallucinations of sleep paralysis.  Credit: Henry Fuseli (1781)

Henry Fuseli’s “The Nightmare” may have been inspired by the chest-crushing sensation and hallucinations of sleep paralysis.
Credit: Henry Fuseli (1781)

No surprises here.

via Live Science:

People who’ve experienced the strange phenomenon of sleep paralysis may feel like they can’t move their body when they’re falling asleep or waking up, or may have hallucinations that there’s a malevolent presence pressing down on them. Now, a new study suggests the phenomenon may have a heritable cause.

In the study, researchers asked a group of more than 800 twins and siblings whether they had experienced sleep paralysis. The results showed that genetics were partially to blame for the strange phenomenon.

In addition, the people in the study who had anxiety, slept poorly or had experienced stress in their lives were more likely to have these nighttime bouts of paralysis, the researchers found.

The findings shed some light on what is still quite a mysterious condition, the researchers said.

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XMED: Craig Venter Estimates 5 Million Complete Human Genomes Sequenced by 2020

venter-xmed

via Singularity Hub:

Researchers finished the first draft of the human genome in the year 2000. Although the decreasing cost of the technology has far outpaced Moore’s Law since then, we have yet to fully leverage all that new information, to make it really useful.

In a wide ranging talk on his work, from transcribing the first complete human genome to building synthetic life forms, genomics pioneer Craig Venter, confessed he was disappointed that genomics has taken as long as it has to scale up.

“We just got to the starting line,” Venter said, speaking at Singularity University’s Exponential Medicine conference. “Hopefully it won’t take as long to get through it as it took to get started.”

What’s changed? Earlier this year, genomic sequencing company, Illumina, announced a new sequencing system that can produce 18,000 high quality human genomes per year at $1,000 per genome—a mark dreamed of for over a decade.

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More Left-Handed Men Are Born During the Winter

Left hand writing the Dutch word "Linkshandig" (left-handed). By Armin Kübelbeck

Left hand writing the Dutch word “Linkshandig” (left-handed). By Armin Kübelbeck

According to a recent study, men born in the winter have a higher chance of being left-handed. But what exactly does that prove?

Via ScienceDaily:

Men born in November, December or January are more likely of being left-handed than during the rest of the year. While the genetic bases of handedness are still under debate, scientists at the Faculty of Psychology, University of Vienna, obtained indirect evidence of a hormonal mechanism promoting left-handedness among men.

Psychologist Ulrich Tran and his colleagues published their findings in the scientific journal Cortex.

Various manual tasks in everyday life require the use of the right hand or are optimized for right-handers. Around 90 percent of the general population is right-handed, only about 10 percent is left-handed. The study of Ulrich Tran, Stefan Stieger, and Martin Voracek comprised two large and independent samples of nearly 13,000 adults from Austria and Germany.

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Pathological Gambling Runs In Families

Hearts Penalty CardsDammit, genes.

Via Eurekalert:

A study by University of Iowa researchers confirms that pathological gambling runs in families and shows that first-degree relatives of pathological gamblers are eight times more likely to develop this problem in their lifetime than relatives of people without pathological gambling.

“Our work clearly shows that pathological gambling runs in families at a rate higher than for many other behavioral and psychiatric disorders,” says Donald W. Black, MD, professor of psychiatry in the UI Carver College of Medicine. “I think clinicians and health care providers should be alerted to the fact that if they see a person with pathological gambling, that person is highly likely to have a close relative with similar or the same problem. That is a teaching moment and they should probably encourage the patient to let their relatives know that help is available.”

Pathological gambling−gambling that is serious enough that it becomes a clinical issue−is a major public health problem that affects between 0.5 and 1.5 percent of American adults at some point during their lives.

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Should Courts Consider Genetic Propensity For Violence When Sentencing?

Photo: CIAT via Flickr (CC)

Photo: CIAT via Flickr (CC)

“Hey listen, I’m not a bad man. I’m sick, see. Sick. What do you call it? Psychopathic. You know. Personality disorder. The court, man, he says so! You’re not gonna hurt me, are you? Jesus! You can’t kill me!” – Johnny the Boy, Mad Max (1979)

In 2009, an Italian court reduced a murderer’s sentence by one year because doctors had identified a gene in the defendant’s DNA, called MAOA, that had been linked to violent behavior. The ruling was controversial and some scientists objected to the sentence reduction. “MAOA findings have been generally used in murder trials, sometimes to suggest diminished capacity of the defendant to premeditate his criminal behavior,” but most often to reduce a sentence, writes Paul Appelbaum, a psychiatrist at Columbia University, in an essay published today in Neuron. In the essay, Appelbaum explains that genetic evidence demonstrating a defendant’s predisposition for antisocial behavior or mental illness is showing up in courtrooms at an ever-quickening pace.

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Modern Human Evolution: Is It Working Against Us?

i-8c66c4d51330345ea25f9764619ec10e-human-evolutionIn the vein of discussion recently on disinfo regarding how politically correct (or morally obligative) it is to address a person’s stupidity, Nicholas Wade writes a challenging and frank article for Time.com to promote his book A Troublesome Inheritance: Genes Race and Human History.

…Racism and discrimination are wrong as a matter of principle, not of science. That said, it is hard to see anything in the new understanding of race that gives ammunition to racists. The reverse is the case. Exploration of the genome has shown that all humans, whatever their race, share the same set of genes. Each gene exists in a variety of alternative forms known as alleles, so one might suppose that races have distinguishing alleles, but even this is not the case. A few alleles have highly skewed distributions but these do not suffice to explain the difference between races. The difference between races seems to rest on the subtle matter of relative allele frequencies.

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You Might Have Inherited Your Ancestors’ Fears

PIC: Hale Woodruff "Ancestral Memory" (CC)

PIC: Hale Woodruff “Ancestral Memory” (CC)

While not widely accepted in psychiatric circles, C.G. Jung’s theories about “racial memory” (more commonly known now as “genetic memory”) became a popular trope in the writings of writers like Robert E. Howard, Jean Auel, and Frank Herbert, all of whom used it to introduce things into their stories that their characters might not otherwise know. Now it seems that a couple of scientists may have proven that there is at least some truth to the idea that we can inherit memories of a sort from our ancestors.

Via Discover Magazine:

Geneticists were especially surprised to find that epigenetic change could be passed down from parent to child, one generation after the next. A study from Randy Jirtle of Duke University showed that when female mice are fed a diet rich in methyl groups, the fur pigment of subsequent offspring is permanently altered. Without any change to DNA at all, methyl groups could be added or subtracted, and the changes were inherited much like a mutation in a gene.

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