Childcare, Genetics, Epigenetics and Schizophrenia
A radical gene theory gains momentum: 'Epigenetics' researchers say life experiences and nutrition affects gene function.
An article by Daniel Tencer of the newspaper Ottawa Citizen (Canada) covers the emerging field of epigenetics, which proposes that there is a "second code" of programming on top of our DNA, a code that -- unlike DNA -- can change during our lifetimes. Following is a summary of the Ottawa Citizen article.
In the past half decade, epigenetics researchers have theorized that our diet, the chemicals we are exposed to and even our behavior toward one another can cause changes in the way our genes are expressed, and contribute (by making people more susceptible to) or trigger mental illnesses like schizophrenia and bipolar disorder - and some of the epigenetic changes may even be passed on to future generations.
That, in turn, has caused many scientists to rethink almost everything we know about how genetic information is passed on from parent to child.
SEISMIC SHIFT IN THINKING
The customary view on genetics has been in terms of black and white; we are born with certain genes, and in term they determine our “physiological existence”. Destiny isn’t written in the stars, but rather in our DNA. Scientists have deviated from this hard coded view, and found that not only are we influenced by our DNA, but our DNA is influenced by us. The life experiences we have, such as the food we eat, the people we meet, and the stress we endure, may alter the functioning of our genes, and the genes we pass on. This is the emergence of the epigenetics theory.
Only 30 year’s young, epigenetics was created to fill in the blanks left by traditional genetic theory. Identical Twins and occurrence of schizophrenia was a large question unanswered through genetic theory. Although identical twins share 100% of their DNA or genes, many cases have found 1 twin developed schizophrenia, while the other did not.
Dr. Arturas Petronis, a prominent researcher from the Canadian Center for Addiction and Mental Health, began examining this twin discordance that occurred in about 50% of the twin cases with schizophrenia, 8 years ago. Although most geneticists believe environmental factors play a significant role in mental illness development, none of them can provide specific information on what that means, or how it works. Petronis hopes that epigenetics may be the missing link. He found greater similarities between psychiatric patients in regards to epigenetic make-up, than when comparing these psychiatric patients to their own identical twins.
"Any two random people share 99.7 per cent of their DNA, but at the epigenetic level, people are very, very different," Petronis says.
CHANGES PASSED ON?
Maybe the most significant finding is the possibility that someone’s epigenetics are hereditary; studies have found evidence that at least parts of the code can be passed down to future generations. Marcus Pembrey, a geneticist from University College London, UK, is leading this theory with studies where he examined medical records of an isolated Swedish city. He found that life experiences and behaviors influenced the health and biology of future generations;
“The grandsons of men who experienced famine during mid-childhood went through puberty earlier and had longer life spans, while the grandsons of men who were well fed in early childhood had an increased likelihood of diabetes. For females, the effect was similar but it was tied to the grandmother, rather than the grandfather.”
Pembrey argues that, "This is not a 'trickle-through' (of genetic material), this is clearly an evolved response," and this response is an adjustment to random or adverse environments.
In later studies of families located in Bristol England, Pembrey found a father who began smoking prior to 11 years of age, produced sons with significantly greater weight than the average. This study provided scientific basis for the theory that our exposures can influence our genetic makeup and even the genes that are passed on to future generations, but even with support the theory is highly controversial.
Because epigenetics is a fairly young science, researchers still know very little about how it works. Even with all the new technologies, we are just beginning to understand genetics alone, and epigenetics is much more complicated. Szyf, editor-in-chief of the new Scientific Journal of Epigenetics paints a picture of the complexity of epigenetics , "Epigenetic codes are moving targets. They could change at any time. And the same gene, one gene, could have 700 epigenetic programs. So that complicates things." Szyf has focused research on connecting social interactions to epigenetic changes, which highlights the vast influence epigenetics may have; even our behaviors and interactions can influence us and our descendants.
Szyf and his colleague Michael Meaney, a researcher at Montreal's Douglas Hospital, found that epigenetic changes were the causes for why rats who were groomed and licked by their mothers, behaved much calmer than their counterparts who were neglected. The nurturing process of grooming and licking activated a gene that suppressed cortisol (a stress hormone) production. Their neglected counterparts didn’t have that activation, and as a result produced the hormone and become much more stressed out. They also found that injecting the calm rats with methionine (an amino acid found in food supplements) produced an increase in their stress levels; this illustrates the significance of simple exposures or changes in diet that can alter the way our genes work.
THE FUTURE OF EPIGENETICS?
Not only do scientists have genetic mapping and understanding on their plate, but they will have to add the understanding and mapping of epigenetics if we want to make significant progress. 2003 marked the beginning of the first Human Epigenome Project, whose goal is to have a mere 10% of the human epigenetic structure mapped by this fall. And they seem to be heading towards this goal, just last month a comprehensive mapping of three human chromosomes. The results showed about one-fifth of the genes from these chromosomes can be altered by exposures.
THE BIG PICTURE…
Things that may not receive a lot of thought in our lives, such as; the food we eat, the chemicals we are exposed to, our social interactions, and even our family’s behaviors toward us, can all have a much more significant impact on our genetic functioning than previously thought.
How to safeguard ourselves and future generations isn’t completely understood, but one thing Prembrey is certain of is the emphasis on child rearing, “Child care has a whole new meaning.”
A Healthy Family Social Environment May Reduce Schizophrenia Risk by 86% for High Genetic Risk Groups
Genome and Epigenetics affects disease in new ways
Genetics of Complex Diseases
Lower level of Family Stress May Reduce Risk of Schizophrenia in Children
Epigenetics and Bipolar Disorder
Psychiatric epigenomics and Schizophrenia
Epigenetic Studies of Chromosome 22 in Major Psychosis
Epigenetics discoveries challenge outdated medical beliefs about DNA, inheritance and gene expression
Wikipedia on Epigenetics
The origin of schizophrenia: genetic thesis, epigenetic antithesis, and resolving synthesis
New study explains the differences in individuals with matching genes
Do identical twins have identical DNA?
WikiPedia on "Identical Twins"
Same Difference: Twins' gene regulation isn't identical
"Although identical twins have identical DNA, they often harbor clear-cut differences: slight variations in appearance or stark distinctions in disease susceptibility, for example. Scientists have suggested that the interplay between nature and nurture could explain such differences, but the mechanism has been poorly understood.
A new study suggests that as identical twins go through life, environmental influences differently affect which genes are turned on and which are switched off.
Called epigenetic modification, such gene activation or silencing typically stems from two types of chemical groups that latch on to chromosomes as charms attach to a bracelet, says Manel Esteller of the Spanish National Cancer Centre in Madrid"
Identical Twins Exhibit Differences in Gene Expression (Scientific American)
Posted by szadmin at August 30, 2006 11:23 PM
More Information on Schizophrenia Biology
This article is another disturbing example of how there are people out there who are fighting tooth and nail to support the nurture vs nature concept of mental illness. Every example or scenario in this excerpt is a very direct example of how genes determine the outcomes of interaction between the human body and environmental factors. This notion of so-call "epi-gentics" is an abstraction. Gentic damage caused by exposure to famine or biological damage caused by exposure to excess cortisol (as a result of family disfunction or poor nurturing) point right back at genetics as we commonly understand it. There is nothing phenomenal in these observations.
I believe that there are individuals who are simply wired to have difficulty with the concepts of genetics. I believe it is possibly even a cognitive deficit. Unfortunately, the field of psychiatry seems to attract too many people who are wired this way. There might even be religious
underpinnings to this type of thinking. There are people out there who need
to find a way to blame mankind for the existence of horrific diseases instead
of the engineer or architect (Who they call God) who apparently intentionally or unintentionally made the human body genetically suseptible for the most
horrific disfunctions of the body.
Posted by: Jennifer at September 5, 2006 08:29 AM
Actually - if you talk with the leading scientists today in biology they'll generally tell you that the old theory of "Nature vs. Nurture" is a false distinction - the new scientific view is that its "Nature AND Nurture" that together influence how disorders and diseases develop (as well as personality, etc.). So the research mentioned above is very consistent with the current view of biologists and other experts. In fact a few years ago there was a good book writen by a Cambridge-PHD writer called "Nature via Nurture" (written by Matt Ridley). Epigenetics may not be the right explanation for this interplay between genes and environment - but the scientific consensus is that environment does have an impact on the expression (or function) of genes, and that environment does have a significant role in schizophrenia; its the only way to explain the data that has been accumulated on schizophrenia.
I'm curious as to how you explain the fact that on average that an identical twin (where their sibling has schizophrenia) - only has about a 50% chance of developing schizophrenia. Given that the genes are identical - what else could it be but "environment"? (and scientists define "environment" to be basically everything other than genes). What is your theory that explains this fact?
Also - how do you explain the fact that adopted children from mothers who have schizophrenia get schizophrenia at about a 38% rate in dsyfunctional families, vs. 5% in healthy families - as shown in the recent 40 year long finish research on the following page:
Posted by: szadmin at September 5, 2006 11:17 AM
"Given that the genes are identical "
there's the first flaw in the logic. identical twins aren't identical genetically.
the fact that studies find less than 100 concordance for schizophrenia between 'identical twins' actually means next to nothing.
too, if one doesn't know the genetic means by which the disease is inherited, it is completely impossible to say what different rates of concordance signify. there is no reason why schizophrenia would have to be 'inherited' in a conventional, well understood fashion. it could be a prion disease, it could be passed by a gene that is affected by other genes, it could require a number of genes additively, or it could be material that is all given to one twin in the early division of the embryo when identical twins form.
Posted by: slc2 at September 7, 2006 02:55 PM
Hi SLC - where exactly do you get your genetics knowledge from? Please cite your sources.
I've added 4 or 5 new links at the bottom of the story - all of which say that identical twins have identical genetics - by definition.
About.com says "Identical, or monozygotic, twins develop from a single egg/sperm combination that splits a few days after conception. Their DNA originates from a single source, thus their genetic makeup is the same"
Science Daily News says: "Although identical twins have identical DNA, they often harbor clear-cut differences: slight variations in appearance or stark distinctions in disease susceptibility, for example. Scientists have suggested that the interplay between nature and nurture could explain such differences, but the mechanism has been poorly understood.
A new study suggests that as identical twins go through life, environmental influences differently affect which genes are turned on and which are switched off.
Called epigenetic modification, such gene activation or silencing typically stems from two types of chemical groups that latch on to chromosomes as charms attach to a bracelet, says Manel Esteller of the Spanish National Cancer Centre in Madrid. Methyl groups that clip on to DNA tend to turn genes off. On the other hand, acetyl groups attaching to histones, the chemical core of chromosomes, usually turn genes on."
So - again, I'm very interested to learn where you get your genetics information from - because its wildy at odds with all the good science sources that I can find.
And please - if you start throwing out new ideas like schizophrenia could be a "prion disease" - please come up with some literature to support your claims, and explain how the prions get impacted so that in a healthy family environment schizophrenia risk is 85% lower than in dysfunctional family environments (for children with high genetic risk).
The good news is that I have a schizophrenia genetics researcher/professor writing a paper on the current state of the art in terms of science knowledge of genetics and schizophrenia - so I hope that will educate all of our visitors on what the experts currently believe. Of course - SLC2 will probably still disagree.
Posted by: Sz Administrator at September 7, 2006 04:19 PM
you sound pretty sure i'm wrong already, despite quotes you provide that support some of the points i brought up...i dont see any possibility of a discussion between us given your stance.
no, no one said schiz is a prion disease, what i am suggesting is that just because an illness doesnt follow a known conventional mendelian pattern doesnt mean it's multifactorial. this has always been my position, and it is is one that i have been attacked for here repeatedly. i'm no longer willing to offer up my evidence for these things if it is only causes me to be attacked in a personal and vindictive manner.
those who are truly curious can write me personally, and i'll furnish them with all the information i have available. but don't bother writing if your goal is to attack me and call me names.
Posted by: slc2 at September 8, 2006 06:02 AM
Hi slc2 - all I'm saying is that if you make a claim (especially a claim that is completely opposite to the state of scientific knowledge in the world - such as when you said that "identical twins don't have identical genes") then you really need to support that claim with facts from good sources.
If you can't do that - then I think you should be re-evaluating the claim you're making. Without evidence all you have are ideas - and ideas don't help families with schizophrenia - evidence does.
Posted by: Sz Administrator at September 8, 2006 09:41 AM
i have posted information here about identical twins several times, and in a number of posts on the bulletin board as well. everyone ignores it, and says i don't post the information. i do - you dont read it.
give it up, folks...'identical twins' are not identical. they are referred to as identical due to tradition and ignorance. you're wrong - that's all. they aren't identical. they are LARGELY identical. that is true.
when the embryo divides, gobs of material can go to one half of the embryo and not the other and identical twins can then differ at that point - no, no one said prions cause schizophrenia, but the fact is that prions can be 'inherited' in two different ways, one genetically, and one that is more as just being carried along on the fetal tissue by a sort of contamination or infection. thus prions - and very likely, genetic material like them that we dont even know anything about yet, can follow distinctly different patterns of occurance and 'heredity' even for the same sort of prion. it's quite likely that viruses and other genetic material can behave in ways we know nothing about yet.
in addition, the differences dont need to stop there. two fetuses then grow and develop, and it's not a given that maternal conditions have to affect both fetuses equally, or that the brain cells in their two separate brains would migrate and hook up exactly the same way.
in addition, genes aren't just 'present'. they aren't static things. they aren't black and white. they are active and dynamic, and genes turn on and off a number of times during the development of the fetus, with a large number of different factors promoting the gene and making it active or inactive.
genetics, genetic material, growth and development, is all complicated by 'stuff we dont know', which is alot.
Posted by: slc2 at September 8, 2006 11:45 AM
Thank you for this article. It makes sense. I have a mother and younger sister with shizophrenia and I KNOW it has both a genetic (nature) and social/living (nurture) source, just witnessing the illness for fifteen years now. Please continue with this line of research. There are still so many questions unanswered but every bit of "out of the box" thinking like this one, brings us closer and maybe brings us to an environment/childhood/medication combination that can help sufferers function and live a happy, unafraid and rich life in reality.
slc2 : all we're asking for is a url that supports your view scientifically by recognised geneticists, not an explanation by yourself. With regards to DNA structure, twins are identical, by definition. The "globs of material" you speak of, uhm... yes, right. As I say, scientific url from a geneticist, please.
Posted by: Adi at November 4, 2006 11:16 PM
I am experiencing loads of attachment to opinion. Let me contribute in that spirit.
Don't let them get away with that , it seems we're often told.
Just fight your corner strongly, until you se them fold.
You'll feel a boost to Ego, a sense of great elation,
For God's sake, never seek some further information.
Copyright Jan F.
Posted by: Jan Fennell at November 13, 2007 04:26 PM