Schizophrenia consists of eight different genetic diseases

Schizophrenia consists of eight different genetic diseases
The researchers at the University of Granada who have participated in this project. From left to right, Rocío Romero Zaliz, Javier Arnedo, Igor Zwir y Coral del Val.

Scientists from the universities of Granada (Spain) and Washington in St Louis (US) have found that there is not a single type of schizophrenia, but that it consists of a group made up of eight genetically different types of diseases, each of which presents its own set of symptoms.

This important find, published recently by the prestigious American Journal of Psychiatry, could be an important first step towards a better diagnosis and treatment of this , which affects approximately 1% of world population.

It was known so far that approximately 80% of the risk of suffering from schizophrenia was hereditary, although have struggled for years to identify which specific genes lead to it.

This new research, in which 4196 patients diagnosed with schizophrenia participated, has for the first time identified the different genes networks that contribute to the existence of eight different types of schizophrenia. In this research other 3200 healthy patients participated as control group.

Genes function as an orchestra

"Genes do not operate on their own, in an isolated manner," Igor Zwir, a researcher at the university of Granada and co-author of his article, pointed out, "they rather work with each other as an orchestra. To understand how they work, we must not just know what each member of this orchestra is like, but also how they interact with each other."

"What we did with this research, after a decade of frustration in the field of psychiatric genetics, is identify the manner in which the genes interact with each other, in an orchestrated manner in the case of healthy patients, or disorganized, as happens in the cases that lead to the different types of schizophrenia," claim the authors of the publication.

Thus, in some patients with hallucinations or delirium, for instance, researchers agree that there are different networks of genes related to their respective symptoms, which demonstrates that specific genetic variations interact with each other. This genetic analysis leads to 95% certainty in predicting the onset of schizophrenia. In another group, they found that incongruent speech and disorganized behaviour are specifically associated with a DNA variations network that leads to a 100% risk of suffering schizophrenia.

Researchers divided the patients according to the type and seriousness of positive symptoms (such as different types of hallucinations or deliriums), or negative symptoms (such as lack of initiative, troubles in organizing thoughts, or lack of connection between emotion and thought). In parallel, scientists classified the profiles of these symptoms into eight qualitative types of different diseases according to the underlying genetic conditions.

Individual genes

"In the past, scientists had searched for associations between individual genes and schizophrenia—researchers point out. What was lacking was the idea that these genes do not act independently, but that they work as a group instead, to disturb the structure and the functions of the brain, thus causing the disease."

Although individual genes only present weak, inconsistent associations with schizophrenia, the interaction networks of gene groups pose a high risk of suffering from the disease, between 70 and 100%, "which makes it almost impossible that individuals with those genetic variation networks will avoid schizophrenia."

Researchers found a total of 42 genes groups that influenced in a variety of ways the risk of suffering schizophrenia. They also replicated their finds in two independent samples of individuals with schizophrenia, an index that these networks are a valid path for the exploration and improvement of the diagnosis and treatment of this disease.

Profesor Zwir points out that, by identifying these networks and their adjustment within the symptoms in individual patients, 'it will soon be possible to determine a possible localized treatment for the specific paths that cause " and he emphasizes the fact that this work, published in the American Journal of Psychiatry, "has been performed and designed by researchers in the field of Computational Science."


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Schizophrenia not a single disease but multiple genetically distinct disorders

More information: Arnedo J, et al. Uncovering the hidden risk architecture of the schizophrenias: confirmation in three independent genome-wide association studies.The American Journal of Psychiatry.vol.172 (2), 2014. www.ncbi.nlm.nih.gov/pubmed/25219520
Journal information: American Journal of Psychiatry

Citation: Schizophrenia consists of eight different genetic diseases (2015, January 13) retrieved 23 May 2019 from https://medicalxpress.com/news/2015-01-schizophrenia-genetic-diseases.html
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Jan 13, 2015
I guarantee these findings won't be replicable (in any case it doesn't sound they took into account epigenetics [which means how environmental factors turn genes on and off], their only "paradigm shift" was to look at groups of genes instead of individual ones).

In any case Emil Kraepelin (who first described the phenomenon [but labelled it as "dementia praecox"] and Eugen Bleuler (who coined the term schizophrenia) both believed they were a category of illnesses (the "schizophrenias") from the get-go, this is nothing new (as sometimes happens, scientists are only "discovering" something which was known and forgotten).

Jan 13, 2015
stuff like this is why i consider the risks of fully defunding the social and psychological sciences from all public dollars a risk worth taking.

utter nonsense. i mean, not even defensible nonsense. just like may as well write an article about the genetics of seahorses contributing to global warming.

Jan 14, 2015
Fact: The country with the best prognosis for schizophrenia is, Ta-da- Mozambique. Eat humble pie, white lab coat.
Fact. The Quakers had this thing beat way back when. And then it was medicalized in order to make a fat profit for Big Pharma. Even the title of this article erroniously calls the condition a "disease". Some people are quite comfortable with their voices. So much for it being a dis-ease.
Conjecture: The patent on Olanzopine is about to run out- Time for a new (Patented) wonder drug.
Homework: Read "Mad in America" for a true Hitchcockian macabre horror story.

Jan 14, 2015
"Mental illness" was medicalized *way before* the invention of psychotropic "medications" (which only occurred in the post World War Two era, although the biomedical paradigm was reinforced by the turn to drugs); guys like Emil Kraepelin and Eugen Bleuler were using a medical lens to describe extreme forms of aberrant behavior around Freud's time not to mention individuals like Benjamin Rush one of the founders of American psychiatry who signed the Declaration of Independence.

Jan 14, 2015
I agree with the study as I observe schizophrenics I know taking street drugs to self-medicate as their condition is undiagnosed in the West. In Russia situation is better because person may be involuntary placed in treatment by relatives whereas in West schizophrenics are allowed to roam at large, often sleeping in their on body waste. Of course problem in Russia is unavailability of legal cannabis stemming from conservative Soviet laws. Problem with schizophrenia is condition blocks person's ability to self diagnose. So they in denial of their condition often requiring involuntary diagnosis and intervention

Jan 14, 2015
Please consider this.
Complex systems display emergent properties.
The brain is a complex system designed to create a mind.
What would stop more than one mind forming in the brain?
How does taking a chemical sledgehammer to the brain kill only the extra minds without affecting the Prime?
Alcohol is one such "neuroleptic". What a pity it cannot be patented- think of all the money that could be made!
Is it ethical to even try to kill these extra minds?
Do they still perform the "wonder treatment" sub orbital lobotomy on moody teenagers? Or is that no longer fashionable?
So what is the current fashion, and how long will it last? Until the patent runs out?
The Quakers had this thing nailed to the floor- the medical approach has been a moral disgrace.

Jan 16, 2015
The most noteworthy aspect I see here is the shift from the old paradigm of "one disease - one cause" beyond the stage of "a disease with multiple interacting causes" to a stage of "multiple related disorders resulting from the interactions of multiple causes".

I see this as a more realistic paradigm for entire suites of disorders - 'mental illnesses' (variant brain dysfunctions with visible behavioral symptoms) such as 'schizophrenia' and 'autism', and cancers (dysfunctions of cellular growth/reproduction mechanisms).

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