Genetic Foundations of Autism?

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> > NATIONAL INSTITUTES OF HEALTH

> >

> > National Institute of Child Health and Human Development

> >

> > NIH NEWS RELEASE

> >

> > FOR IMMEDIATE RELEASE

> >

> > Wednesday, August 22, 2001

> >

> > Contact: Braddock or Bock

> > (301) 496-5133

> >

> > RESEARCHERS FIND NEW INSIGHTS INTO

> > THE GENETIC FOUNDATIONS OF AUTISM

> >

> > In collaboration with their European colleagues, scientists

> > funded by the National Institutes of Health (NIH) have come

> > one step closer to determining the genetic basis for

> > autism. The researchers have identified regions of four

> > chromosomes that appear to be linked with the disorder.

> >

> > " These findings confirm the role of genetics in autism and

> > are a major step in narrowing the search for the specific

> > genes involved, " said Duane , M.D., Director of

> > the National Institute of Child Health and Human

> > Development (NICHD) and co-chair of NIH's Autism

> > Coordinating Committee.

> >

> > At least one in 500 people are affected by some form of

> > autism, a neurodevelopmental disorder that causes problems

> > with communication and social interaction, as well as

> > repetitive actions and interests. Earlier studies with

> > families and twins have shown that there is likely to be a

> > strong inherited component to autism. Because of the wide

> > range of patients' symptoms, many researchers suspect the

> > disorder is the result of a complex interaction between

> > several different genes involved with brain signaling and

> > development. Unidentified environmental factors are also

> > likely to play a role.

> >

> > In this study, researchers screened the DNA of more than

> > 150 pairs of siblings with autism. They found extremely

> > strong evidence that two regions on chromosomes 2 and 7

> > contain genes that are involved with autism. Likely

> > locations for autism-related genes were also found on

> > chromosomes 16 and 17, although the strength of the

> > correlation was somewhat weaker. The findings will appear

> > in the September issue of the " American Journal of Human

> > Genetics. "

> >

> > Chromosome 7 is known to be associated with many language

> > disorders and has been shown to be linked with autism in

> > some earlier studies, but not all.

> >

> > " Because of the size of this study and the strength of the

> > correlation found, there is now little doubt that the so-

> > called language disorder chromosome is significantly

> > involved with the development of autism, " said Marie

> > Bristol-Power, Ph.D., NICHD Special Assistant for Autism.

> >

> > Researchers were particularly excited by evidence of an

> > autism link on chromosome 2, since this area had recently

> > been identified by another, independent research group.

> > NICHD is currently supporting a range of research looking

> > at the interaction between the genes for early brain

> > development located on chromosome 2 and environmental

> > influences.

> >

> > " We wouldn't be looking for genes on chromosome 2 if not

> > for these findings. Now we can be fairly certain that

> > genes on chromosomes 2 and 7 are linked with autism, " said

> > Dr. Ed Cook from the University of Chicago, a participating

> > researcher on the project.

> >

> > Dr. Bristol-Power noted that the project's international

> > scope was critical in getting a sufficiently large number

> > of patients who were diagnosed using the same methods.

> > Drawing DNA from a large number of people allows

> > researchers to make more definitive claims of linkage

> > between the DNA region and the disease.

> >

> > " Teams from all over the world worked together to produce

> > this result, " said Dr. Bristol-Power. " This kind of

> > collaboration is how the problem of autism will eventually

> > get solved. Even larger numbers, 400-500 pairs of

> > relatives, are needed to get more definitive answers, and

> > collaborative international efforts to complete a genome

> > scan on such numbers are now underway. "

> >

> > This work was carried out by members of the International

> > Molecular Genetic Study of Autism Consortium, a group of

> > clinicians and scientists from the UK, USA, France, the

> > Netherlands, Denmark, Italy, and Greece. (For more

> > information, see website

> > http://www.well.ox.ac.uk/~maestrin.iat.html.) The US

> > component of their work was conducted as a part of the

> > Yale/University of Chicago/UCLA Collaborative Program of

> > Excellence in Autism (CPEA), part of the Network on the

> > Neurobiology and Genetics of Autism, a research initiative

> > funded by NICHD and the National Institute on Deafness and

> > Other Communication Disorders.