Autism-Schizophrenia genetic link
Dec. 3rd, 2009 04:03 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
ltmurnauThis is interesting....
Autism and schizophrenia linked to faults in same genes: Study
By Randy Shore, For Canwest News Service
December 3, 2009 8:12
METRO VANCOUVER – Simon Fraser University researchers have found that autism and schizophrenia are both caused by faults in the same set of genes, raising hopes that an effective test or treatment for one may be adapted for use on the other.
The finding is a radical departure from conventional medical thinking about the two disorders as separate and distinct illnesses, according to evolutionary biologist Bernard Crespi, but it opens the door to new avenues of research into the cause and potential cure for each.
Crespi and his co-authors, Philip Stead and Michael Elliot, now believe that autism and schizophrenia are related but opposite illnesses, each caused by anomalies in the same places in the human genome, our genetic blueprint.
Knowing where to look in the genome could help scientists identify which of the dozens of gene mutations that can lead to autism and schizophrenia are peculiar to both. Researchers hope that treatments can then be tailored very specifically and exploited, in different ways, to treat both disorders.
"It’s just like what people are actually doing now with cancer," Crespi explained. By identifying certain receptors on cancer cells, drug treatment can be designed to target them specifically.
"In principle, something very similar can be done with autism and schizophrenia," he opined.
A drug to treat schizophrenics that increases activity in certain chemical pathways in the brain could point the way to a drug that decreases the same activity and prove useful for treating autism.
"You could develop opposite therapeutic treatments," Crespi said. "That’s one of the direct implications if the disorders are opposites."
Crespi, Stead and Elliot are forging a new path, mostly alone.
The idea that autism and schizophrenia are disorders on a single continuum had been proposed by psychologist Daniel Nettle, who coined the idea based on studies of patient behaviour, but had not tested the notion genetically.
"Autism and schizophrenia have always been regarded as being quite similar, but our data pretty much says the opposite," Crespi said. "The idea of two psychiatric illnesses being opposites is quite a controversial one."
Both illnesses involve a malfunction in understanding and processing social signals and behaviours, but in opposite ways, he said. Severe autistics cannot interact socially and may regard other people as little more than objects. Schizophrenics attach too much meaning to people and their actions, perceiving intentions and relationships that do not exist.
Perceiving meaning, a sense of self and complex social interaction represent the most recent advances in human evolution and in autistics, those abilities are severely curtailed while in schizophrenics they are overactive.
"It’s like there is a switch that can dial human evolution up and down," Crespi said.
The SFU group found that variations in four sets of genes are related to both autism and schizophrenia. People normally have two copies of each gene, but in autistics some genome locations have only single copies and in schizophrenics extra copies are present at the same locations.
The same anomalies also appear to influence abnormal brain growth and head size, with overdevelopment of the brain common in autistics and underdevelopment associated with schizophrenia. Crespi says the brain size associations are consistent with his theory that autism and schizophrenia are diametric conditions.
rshore@vancouversun.com
© Copyright (c) Canwest News Service
I have always been of the tendency that both were genetically caused, at least enough for a predisposition. I agree it would be nice if some form of therapy could be discovered for either, or both. However, I don't know if I like the metaphor of "dialing human evolution up and down", but then again, I'm not supposed to be able to comprehend figurative language in the first place.
CBC wrote it up a little differently:
Mutations link autism, schizophrenia: study
Last Updated: Thursday, December 3, 2009 | 11:44 AM PT
CBC News
Autism and schizophrenia may be genetic opposites, an evolutionary biologist in British Columbia says.
Bernard Crespi of Simon Fraser University and his colleagues analyzed data on all known genetic variants linked to both conditions.
Crespi thinks that autism and schizophrenia are diametric opposites in how they affect gene activity in specific regions of the brain.
The researchers looked at four regions in the human genome where mutations known as copy number variants can arise — stretches of DNA that contain accidental duplications or deletions. Instead of the usual two copies, one or three copies may be found.
The investigators found deletion mutations in people with autism and duplications in people with schizophrenia, the team reported in this week's online issue of the Proceedings of the of the National Academy of Sciences.
Crespi said the immediate importance of the finding is that if autism and schizophrenia are proven to be opposites, then researchers working on a therapy for one illness may be able to consider new directions for the other.
"The conceptual framework of one disorder will illuminate the study of the other," he told CBC News.
This could be true for both drugs and cognitive behaviour or talk therapy, since drugs working on receptors in the brain could be dialled down for one condition and made to work more for the other.
The findings fit with data from studies of head and brain sizes that show autism is commonly associated with developmentally enhanced brain growth while people with schizophrenia tend to show reduced brain growth.
The copy number variants are very rare events. When they do occur, the odds of getting autism or schizophrenia increase dramatically, Crespi said.
Autism and schizophrenia linked to faults in same genes: Study
By Randy Shore, For Canwest News Service
December 3, 2009 8:12
METRO VANCOUVER – Simon Fraser University researchers have found that autism and schizophrenia are both caused by faults in the same set of genes, raising hopes that an effective test or treatment for one may be adapted for use on the other.
The finding is a radical departure from conventional medical thinking about the two disorders as separate and distinct illnesses, according to evolutionary biologist Bernard Crespi, but it opens the door to new avenues of research into the cause and potential cure for each.
Crespi and his co-authors, Philip Stead and Michael Elliot, now believe that autism and schizophrenia are related but opposite illnesses, each caused by anomalies in the same places in the human genome, our genetic blueprint.
Knowing where to look in the genome could help scientists identify which of the dozens of gene mutations that can lead to autism and schizophrenia are peculiar to both. Researchers hope that treatments can then be tailored very specifically and exploited, in different ways, to treat both disorders.
"It’s just like what people are actually doing now with cancer," Crespi explained. By identifying certain receptors on cancer cells, drug treatment can be designed to target them specifically.
"In principle, something very similar can be done with autism and schizophrenia," he opined.
A drug to treat schizophrenics that increases activity in certain chemical pathways in the brain could point the way to a drug that decreases the same activity and prove useful for treating autism.
"You could develop opposite therapeutic treatments," Crespi said. "That’s one of the direct implications if the disorders are opposites."
Crespi, Stead and Elliot are forging a new path, mostly alone.
The idea that autism and schizophrenia are disorders on a single continuum had been proposed by psychologist Daniel Nettle, who coined the idea based on studies of patient behaviour, but had not tested the notion genetically.
"Autism and schizophrenia have always been regarded as being quite similar, but our data pretty much says the opposite," Crespi said. "The idea of two psychiatric illnesses being opposites is quite a controversial one."
Both illnesses involve a malfunction in understanding and processing social signals and behaviours, but in opposite ways, he said. Severe autistics cannot interact socially and may regard other people as little more than objects. Schizophrenics attach too much meaning to people and their actions, perceiving intentions and relationships that do not exist.
Perceiving meaning, a sense of self and complex social interaction represent the most recent advances in human evolution and in autistics, those abilities are severely curtailed while in schizophrenics they are overactive.
"It’s like there is a switch that can dial human evolution up and down," Crespi said.
The SFU group found that variations in four sets of genes are related to both autism and schizophrenia. People normally have two copies of each gene, but in autistics some genome locations have only single copies and in schizophrenics extra copies are present at the same locations.
The same anomalies also appear to influence abnormal brain growth and head size, with overdevelopment of the brain common in autistics and underdevelopment associated with schizophrenia. Crespi says the brain size associations are consistent with his theory that autism and schizophrenia are diametric conditions.
rshore@vancouversun.com
© Copyright (c) Canwest News Service
I have always been of the tendency that both were genetically caused, at least enough for a predisposition. I agree it would be nice if some form of therapy could be discovered for either, or both. However, I don't know if I like the metaphor of "dialing human evolution up and down", but then again, I'm not supposed to be able to comprehend figurative language in the first place.
CBC wrote it up a little differently:
Mutations link autism, schizophrenia: study
Last Updated: Thursday, December 3, 2009 | 11:44 AM PT
CBC News
Autism and schizophrenia may be genetic opposites, an evolutionary biologist in British Columbia says.
Bernard Crespi of Simon Fraser University and his colleagues analyzed data on all known genetic variants linked to both conditions.
Crespi thinks that autism and schizophrenia are diametric opposites in how they affect gene activity in specific regions of the brain.
The researchers looked at four regions in the human genome where mutations known as copy number variants can arise — stretches of DNA that contain accidental duplications or deletions. Instead of the usual two copies, one or three copies may be found.
The investigators found deletion mutations in people with autism and duplications in people with schizophrenia, the team reported in this week's online issue of the Proceedings of the of the National Academy of Sciences.
Crespi said the immediate importance of the finding is that if autism and schizophrenia are proven to be opposites, then researchers working on a therapy for one illness may be able to consider new directions for the other.
"The conceptual framework of one disorder will illuminate the study of the other," he told CBC News.
This could be true for both drugs and cognitive behaviour or talk therapy, since drugs working on receptors in the brain could be dialled down for one condition and made to work more for the other.
The findings fit with data from studies of head and brain sizes that show autism is commonly associated with developmentally enhanced brain growth while people with schizophrenia tend to show reduced brain growth.
The copy number variants are very rare events. When they do occur, the odds of getting autism or schizophrenia increase dramatically, Crespi said.
