Long! Autism and Genetics - was Re: FW: National Asperger's Society

[Guest guest]

In a timely article from the Schafer Report, see below. Notice how

many children have de novo " chromosomal abnormalities " that wouldn't

be expected given the averages (epigenetics anyone?? notice how the

author doesn't discuss WHY these changes are taking place, ie, what

on earth could be causing so much damage to the chromosomes in the

first place). Also notice that the most prevalent change was found

in, ta dum! ONE percent of the ASD people they studied. ONE PER

CENT. Yet what percentage of ASD people have gut issues, or heavy

metal toxicity, or nutritional deficiencies--yet these are not worth

spending gov't money to investigate.

I also wonder how the person who wrote this article would define

substantial?

Off to bang my head on the floor.

Anita

RESEARCH

Chromosomal Abnormalities

Play Substantial Role In Autism

tinyurl.com/3bnes4

ScienceDaily — Genome-wide scans of families affected by autism

spectrum disorder (ASD) have revealed new evidence that previously

unknown chromosomal abnormalities have a substantial role in the

prevalent developmental disorder, according to a new report.

Structural variants in the chromosomes were found to influence ASD

with sufficiently high frequency to suggest that genomic analyses be

considered in routine clinical workup, according to the researchers.

" Historical studies in identical twins and their families have

provided strong evidence for a genetic basis of autism, " said

Scherer of The Hospital for Sick Children and the University of

Toronto. " Last year, with the Autism Genome Project Consortium, we

did an initial study to look at the rate of chromosomal changes in

autism. Now, we've really pinned down those numbers. "

Autism is a complex developmental disorder found in about one

in every 165 children, making it one of the most common forms of

developmental disability of childhood. Individuals with ASD have

deficits in social interaction and communication and show a

preference for repetitive, stereotyped activities. Structural

changes, including gains and losses of genes as well as chromosomal

translocations (in which a chromosomal segment ends up in the wrong

place) or inversions (in which a portion of the genome is oriented

backwards) have been previously identified in some individuals with

ASD, but their causal role hasn't been clear.

In the new study, the researchers examined structural

abnormalities in 427 unrelated ASD cases using both microarray

analysis and karyotyping. Microarrays can detect " unbalanced " genetic

changes that alter the number of copies of a particular gene.

Karyotyping, in which chromosomes are viewed under the microscope,

can identify " balanced " translocations or inversions that might

otherwise be missed by microarrays.

While most chromosomal abnormalities were inherited, the

researchers found that seven percent of children with autism carry

structural changes in the genome that are not found in their parents.

The rate of such de novo changes in the general population is

typically less than one percent, Scherer said.

The researchers detected 13 regions of the genome with

overlapping or recurrent chromosomal changes in unrelated people with

autism, suggesting that genes located at these sites may cause or add

to the complexity of the condition. The most prevalent change,

occurring in one percent of ASD cases, was found on chromosome 16,

they reported. The altered portion of chromosome 16 has structural

characteristics that make it more prone to errors, Scherer noted.

In a subset of ASD cases, the researchers found abnormalities

in several genes known to be involved in neuron function. They also

identified at least two sites that have previously been linked to

mental retardation.

" Our understanding of the full etiologic role of structural

variation in ASD will require genomic and phenotypic analyses of more

cases (and their families) and population controls, " the researchers

concluded. As a first step toward achieving the desired numbers, the

researchers have established a new Autism Chromosome Rearrangement

Database, which allows integration of their new data and all other

molecular information with the wealth of karyotypic data gathered

over the years.

In light of the new findings, Scherer's team also calls for new

testing in the clinic.

" From our current data it is already apparent that for a

proportion of individuals, it will be possible to describe their ASD

based on the underlying structural characteristics of their genome, "

they wrote.

" If we found certain changes, we could then watch those

children closer, " Scherer added, noting the critical importance of

early diagnosis for autism.

This research was published online Jan. 17th in the American

Journal of Human Genetics, a publication of Cell Press.

> > > > > >

> > > > > >

> > > > > > In a message dated 21/01/2008 10:38:14 GMT Standard Time,

> > > > > > bobsallyeva@ writes:

> > > > > >

> > > > > > he's not really , he's talking about a genetic pre-

> > disposition

> > > > > and

> > > > > > inter-action between genes and environment. Both of those

> > > suggest that

> > > > > > intervention can work.

> > > > > >

> > > > >

> > > > >

> > > > >

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> Date:

> > > 20/01/2008 14:15

> > > > >

> > > >

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