 |
| Health News > New Study Links Autism to Genes that Influence Brain Cell Connections | 
|
ADVERTISEMENT | ADVERTISE WITH US
Health News Videos
The Importance of Monitoring Vitamin D Status in the U.S.
Dr. Howard Nash
The Importance of Monitoring Vitamin D Status in the U.S.
Dr. Howard Nash
The NIH Common Fund's Human Microbiome Project
Top News
Subscribe to this feed:
« Back
Via NIH Press - In three studies, including the most comprehensive study of autism genetics to date, investigators funded in part by the National Institutes of Health have identified common and rare genetic factors that affect the risk of autism spectrum disorders. The results point to the importance of genes that are involved in forming and maintaining the connections between brain cells.
"These findings establish that genetic factors play a strong role in autism spectrumdisorder," says Acting NIH Director Raynard Kington, M.D., Ph.D. "Detailed analysisof the genes and how they affect brain development is likely to yield betterstrategies for diagnosing and treating children with autism."
Autism spectrum disorders (ASD) comprise a group of disorders with core symptomsthat include social interaction problems, poor verbal and nonverbal communicationand repetitive behaviors. These disorders range from severe (autism) to mild(Asperger?s syndrome), and in total affect some 1 in 150 American children, aboutthree-quarters of whom are boys. Researchers theorize that the social parts ofthe brain are underdeveloped in ASD. "Previous studies have suggested that autism is a developmental disorder resultingfrom abnormal connections in the brain.
These three studies suggest some of thegenetic factors which might lead to abnormal connectivity," says Thomas Insel,M.D., director of NIH?s National Institute of Mental Health (NIMH). The studies were funded in part by the NIMH, the National Institute of NeurologicalDisorders and Stroke (NINDS), the Eunice Kennedy Shriver National Institute ofChild Health and Human Development (NICHD), the National Institute on Deafnessand Other Communication Disorders (NIDCD) and the National Center for ResearchResources (NCRR), all components of NIH. All three studies were genome-wide association studies, which are undertakento find clues about the causes of complex disorders.
Typically, these studiesinvolve scanning the genome ? the entire set of DNA ? for small differences betweenpeople who have a disorder and people who do not. The largest study, reported in Nature, involved more than 10,000 subjects, includingindividuals with ASD, their family members and other volunteers from across theU.S. The study was led by Hakon Hakonarson, M.D., Ph.D., a professor at the Universityof Pennsylvania School of Medicine and director of the Center for Applied Genomicsat The Children?s Hospital of Philadelphia. Among other principal investigatorson the study were Gerard D. Schellenberg, Ph.D., also a professor at the Universityof Pennsylvania School of Medicine; and Daniel Geschwind, M.D., Ph.D., a professorat the University of California, Los Angeles and director of UCLA?s Center forAutism Research and Treatment; and Margaret Pericak-Vance, Ph.D., a professorat the University of Miami Miller School of Medicine and director of the MiamiInstitute for Human Genomics, who also led an independent study that generatedsimilar results.
Major funding for Dr. Hakonarson?s work came from The Children?s Hospital ofPhiladelphia. Dr. Pericak-Vance?s work was supported in part by the Hussman Foundation.The DNA samples came from a repository called the Autism Genetic Resource Exchange(AGRE), and from subjects recruited at clinics in Philadelphia, Miami, Los Angelesand other sites. AGRE is run by Autism Speaks, with partial support from NIMH. Previous studies of twins with ASD, other children with ASD and their relativesprovided evidence of a strong genetic contribution. Yet until now, only a fewgenetic risk factors had been identified, and most of those turned out to berare, with unclear significance for ASD in the general population. Researcherscame to realize that the genetics of ASD is complex.
"There are going to be many genes involved in causing autism," says Dr. Hakonarson. "Inmost cases, it?s likely that each gene contributes a small amount of risk, andinteracts with other genes and environmental factors to trigger the onset ofdisease." In their large study, Dr. Hakonarson and his colleagues found several geneticvariants that were commonly associated with ASD, all of them pointing to a spotbetween two genes on chromosome 5, called CDH9 and CDH10. Both genes encode cadherins ? cellsurface proteins that enable cells to adhere to each other.
The researchers alsofound that a group of about 30 genes that encode cell adhesion proteins (includingcadherins and neurexins) were more strongly associated with ASD than all othergenes in their data set. In the developing brain, cell adhesion proteins enableneurons to migrate to the correct places and to connect with other neurons. In a second study, Dr. Pericak-Vance completed an independent search for smallgenetic variants associated with ASD, in collaboration with Jonathan Haines,Ph.D., of Vanderbilt University Medical Center in Nashville. Published in theAnnals of Human Genetics, the study provides a striking confirmation that ASDis associated with variation near CDH9 and CDH10.
"We are starting to see genetic pathways in ASD that make sense," says Dr. Pericak-Vance. Finally, in a third study, reported in Nature, Drs. Hakonarson and Schellenbergled a search for genes that were duplicated or deleted in individuals with ASD.In the rare cases where those variations occurred, many tended to affect genesinvolved in cell adhesion. Others tended to affect genes involved in the ubiquitin-proteasomesystem, a cellular waste disposal system that probably affects the turnover ofadhesion proteins at the cell surface. Previous, smaller genetic studies reported a connection between male-only autismand CNTNAP2, a type of neurexin. Together, the three new studies suggest thatgenetic differences in cell-to-cell adhesion could influence susceptibility toASD on a large scale.
Dr. Hakonarson and his colleagues are planning an evenmore extensive genome-wide association study to gain a more complete pictureof the genes and gene interactions involved in ASD. The mission of NIMH (www.nimh.nih.gov) is to reduce the burden of mental andbehavioral disorders through research on mind, brain and behavior.?NICHD (www.nichd.nih.gov) sponsors research on development, before andafter birth; maternal, child, and family health; reproductive biology and populationissues; and medical rehabilitation.NIDCD (www.nidcd.nih.gov) supports and conductsresearch and research training on the normal and disordered processes of hearing,balance, smell, taste, voice, speech and language and provides health information,based upon scientific discovery, to the public.?
NCRR (www.ncrr.nih.gov) provideslaboratory scientists and clinical researchers with the resources and trainingthey need to understand, detect, treat and prevent a wide range of diseases.NCRR supports all aspects of translational and clinical research, connectingresearchers, patients and communities across the nation.NINDS (www.ninds.nih.gov) is the nation?s primary supporter of biomedical research on the brain and nervous system.
New Study Links Autism to Genes that Influence Brain Cell Connections
| Apr 28th 2009 | Diseases Autism |
Via NIH Press - In three studies, including the most comprehensive study of autism genetics to date, investigators funded in part by the National Institutes of Health have identified common and rare genetic factors that affect the risk of autism spectrum disorders. The results point to the importance of genes that are involved in forming and maintaining the connections between brain cells.
"These findings establish that genetic factors play a strong role in autism spectrumdisorder," says Acting NIH Director Raynard Kington, M.D., Ph.D. "Detailed analysisof the genes and how they affect brain development is likely to yield betterstrategies for diagnosing and treating children with autism."
Autism spectrum disorders (ASD) comprise a group of disorders with core symptomsthat include social interaction problems, poor verbal and nonverbal communicationand repetitive behaviors. These disorders range from severe (autism) to mild(Asperger?s syndrome), and in total affect some 1 in 150 American children, aboutthree-quarters of whom are boys. Researchers theorize that the social parts ofthe brain are underdeveloped in ASD. "Previous studies have suggested that autism is a developmental disorder resultingfrom abnormal connections in the brain.
These three studies suggest some of thegenetic factors which might lead to abnormal connectivity," says Thomas Insel,M.D., director of NIH?s National Institute of Mental Health (NIMH). The studies were funded in part by the NIMH, the National Institute of NeurologicalDisorders and Stroke (NINDS), the Eunice Kennedy Shriver National Institute ofChild Health and Human Development (NICHD), the National Institute on Deafnessand Other Communication Disorders (NIDCD) and the National Center for ResearchResources (NCRR), all components of NIH. All three studies were genome-wide association studies, which are undertakento find clues about the causes of complex disorders.
Typically, these studiesinvolve scanning the genome ? the entire set of DNA ? for small differences betweenpeople who have a disorder and people who do not. The largest study, reported in Nature, involved more than 10,000 subjects, includingindividuals with ASD, their family members and other volunteers from across theU.S. The study was led by Hakon Hakonarson, M.D., Ph.D., a professor at the Universityof Pennsylvania School of Medicine and director of the Center for Applied Genomicsat The Children?s Hospital of Philadelphia. Among other principal investigatorson the study were Gerard D. Schellenberg, Ph.D., also a professor at the Universityof Pennsylvania School of Medicine; and Daniel Geschwind, M.D., Ph.D., a professorat the University of California, Los Angeles and director of UCLA?s Center forAutism Research and Treatment; and Margaret Pericak-Vance, Ph.D., a professorat the University of Miami Miller School of Medicine and director of the MiamiInstitute for Human Genomics, who also led an independent study that generatedsimilar results.
Major funding for Dr. Hakonarson?s work came from The Children?s Hospital ofPhiladelphia. Dr. Pericak-Vance?s work was supported in part by the Hussman Foundation.The DNA samples came from a repository called the Autism Genetic Resource Exchange(AGRE), and from subjects recruited at clinics in Philadelphia, Miami, Los Angelesand other sites. AGRE is run by Autism Speaks, with partial support from NIMH. Previous studies of twins with ASD, other children with ASD and their relativesprovided evidence of a strong genetic contribution. Yet until now, only a fewgenetic risk factors had been identified, and most of those turned out to berare, with unclear significance for ASD in the general population. Researcherscame to realize that the genetics of ASD is complex.
"There are going to be many genes involved in causing autism," says Dr. Hakonarson. "Inmost cases, it?s likely that each gene contributes a small amount of risk, andinteracts with other genes and environmental factors to trigger the onset ofdisease." In their large study, Dr. Hakonarson and his colleagues found several geneticvariants that were commonly associated with ASD, all of them pointing to a spotbetween two genes on chromosome 5, called CDH9 and CDH10. Both genes encode cadherins ? cellsurface proteins that enable cells to adhere to each other.
The researchers alsofound that a group of about 30 genes that encode cell adhesion proteins (includingcadherins and neurexins) were more strongly associated with ASD than all othergenes in their data set. In the developing brain, cell adhesion proteins enableneurons to migrate to the correct places and to connect with other neurons. In a second study, Dr. Pericak-Vance completed an independent search for smallgenetic variants associated with ASD, in collaboration with Jonathan Haines,Ph.D., of Vanderbilt University Medical Center in Nashville. Published in theAnnals of Human Genetics, the study provides a striking confirmation that ASDis associated with variation near CDH9 and CDH10.
"We are starting to see genetic pathways in ASD that make sense," says Dr. Pericak-Vance. Finally, in a third study, reported in Nature, Drs. Hakonarson and Schellenbergled a search for genes that were duplicated or deleted in individuals with ASD.In the rare cases where those variations occurred, many tended to affect genesinvolved in cell adhesion. Others tended to affect genes involved in the ubiquitin-proteasomesystem, a cellular waste disposal system that probably affects the turnover ofadhesion proteins at the cell surface. Previous, smaller genetic studies reported a connection between male-only autismand CNTNAP2, a type of neurexin. Together, the three new studies suggest thatgenetic differences in cell-to-cell adhesion could influence susceptibility toASD on a large scale.
Dr. Hakonarson and his colleagues are planning an evenmore extensive genome-wide association study to gain a more complete pictureof the genes and gene interactions involved in ASD. The mission of NIMH (www.nimh.nih.gov) is to reduce the burden of mental andbehavioral disorders through research on mind, brain and behavior.?NICHD (www.nichd.nih.gov) sponsors research on development, before andafter birth; maternal, child, and family health; reproductive biology and populationissues; and medical rehabilitation.NIDCD (www.nidcd.nih.gov) supports and conductsresearch and research training on the normal and disordered processes of hearing,balance, smell, taste, voice, speech and language and provides health information,based upon scientific discovery, to the public.?
NCRR (www.ncrr.nih.gov) provideslaboratory scientists and clinical researchers with the resources and trainingthey need to understand, detect, treat and prevent a wide range of diseases.NCRR supports all aspects of translational and clinical research, connectingresearchers, patients and communities across the nation.NINDS (www.ninds.nih.gov) is the nation?s primary supporter of biomedical research on the brain and nervous system.
Related articles
- Citalopram No Better Than Placebo for Children with Autism (ASD)
- Autism Skews Developing Brain with Synchronous Motion and Sound
- NIH Will Use 60 Million in Recovery Act Funds to Support Strategic Autism Research
- Thin Bones Seen In Boys with Autism and Autism Spectrum Disorder
Add your own comments
Comments:
No commentsHealth Resource Centers
|
Copyright 2009-2010 Emma Concepts, Inc. All rights reserved. |
About us & FAQ |
Terms of Service |
Privacy Policy |
Advertise
Healthimize.com’s content is for educational purposes only and this page and other pages on Healthimize do not contain medical advice. The information on this website is not a substitute for professional medical advice. Users further agree to abide by the terms of service. Trademarks are properties of their respective owners. |