Navigate Up
UPMC/University of Pittsburgh Schools of the Health Sciences
For Journalists
Senior Manager
Telephone: 412-578-9193 or 412-624-3212
Director
Telephone: 412-417-2582
Other Inquiries

Additive Effect of Small Gene Variations Can Increase Risk of Autism Spectrum Disorders

PITTSBURGH, Oct. 15, 2012 – An increased risk of autism spectrum disorders (ASD) could result from an accumulation of many small, common gene genetic variations rather than large-effect, rare changes in the genetic code, according to a multicenter team led by researchers at the University of Pittsburgh School of Medicine. Their findings, published today in Molecular Autism, provide new insights into the genetic factors that underlie the neurodevelopmental condition.
 
Scientists have debated about the genetic contributions that lead to ASD in families where only one individual is affected, called simplex, versus those that have multiple affected family members, called multiplex, said senior author Bernie Devlin, Ph.D., associate professor, Department of Psychiatry, University of Pittsburgh School of Medicine.
 
“Our team compared simplex, multiplex and unaffected families using sophisticated quantitative genetic techniques,” he said. “In families where only one child has an ASD, 40 percent of the risk is inherited while iIn families with more than one affected child, the risk rises to 60 percent.”
 
For the project, the team examined thousands of DNA samples from families in the Simons Simplex Collection, in which one child but no parent or sibling had an ASD; the Autism Genome Project, in which more than one child had an ASD; and unaffected families enrolled in the HealthABC Program.
 
In addition to reviewing nearly 1 million gene variations, called single nucleotide polymorphisms (SNPs), to look for inheritance patterns associated with ASD, they also ran computer simulations to plot family trees using 1,000 SNPs that appear to impact the risk of ASD.
 
“These small gene changes can add up even though individually they do little harm,” Dr. Devlin said. “This might explain why parents who do not have autism traits can have children who do.”
 
Other research has shown that autism and related disorders can also arise from spontaneous variations in parental genes prior to conception as well as rare mutations of larger effect that are passed on, he noted. The multiple inheritance patterns could help explain the range of symptoms in the disorder.
 
The team included researchers from Yale University, the University of Michigan, University of California Los Angeles, Emory University, Harvard University and others. The effort was funded by grants from the Simons Foundation and National Institutes of Health grant MH057881.

©  UPMC | Affiliated with the University of Pittsburgh Schools of the Health Sciences
Supplemental content provided by A.D.A.M. Health Solutions. All rights reserved.

For help in finding a doctor or health service that suits your needs, call the UPMC Referral Service at 412-647-UPMC (8762) or 1-800-533-UPMC (8762). Select option 1.

UPMC is an equal opportunity employer. UPMC policy prohibits discrimination or harassment on the basis of race, color, religion, ancestry, national origin, age, sex, genetics, sexual orientation, marital status, familial status, disability, veteran status, or any other legally protected group status. Further, UPMC will continue to support and promote equal employment opportunity, human dignity, and racial, ethnic, and cultural diversity. This policy applies to admissions, employment, and access to and treatment in UPMC programs and activities. This commitment is made by UPMC in accordance with federal, state, and/or local laws and regulations.

Medical information made available on UPMC.com is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have. Further, UPMC.com is not a tool to be used in the case of an emergency. If an emergency arises, you should seek appropriate emergency medical services.

For UPMC Mercy Patients: As a Catholic hospital, UPMC Mercy abides by the Ethical and Religious Directives for Catholic Health Care Services, as determined by the United States Conference of Catholic Bishops. As such, UPMC Mercy neither endorses nor provides medical practices and/or procedures that contradict the moral teachings of the Roman Catholic Church.

© UPMC
Pittsburgh, PA, USA UPMC.com