Re: Genetic Hot Spot for Autism?

[Guest guest]

" The scans found that in just over 1 percent

of people with autism, a chunk of about 25 genes had been either

duplicated or deleted, mainly in spontaneous mutations not carried

by their parents. "

I would like them to research to see which vaccine did that.

Gayatri

>

> Rare genetic hot spot is linked to autism

> By Carey Goldberg, Globe Staff | January 10, 2008

>

> Boston-based autism researchers have pinpointed a genetic hot spot

> where DNA errors appear to increase a child's chances of developing

> autism one-hundred-fold.

>

> The discovery, reported online in the New England Journal of

> Medicine yesterday, stems from the most extensive genome scanning

> for autism done so far. The scans found that in just over 1 percent

> of people with autism, a chunk of about 25 genes had been either

> duplicated or deleted, mainly in spontaneous mutations not carried

> by their parents.

>

> Some researchers believe that such errors help explain how autism

> can often crop up in families seemingly out of nowhere. Diagnoses

of

> autism have skyrocketed in recent years, and the disorder now

> affects an estimated 1 in 150 American children.

>

> " It's like having a recipe where you take some of the ingredients

> and use half as much or twice as much, " said Dr. T. of

> Children's Hospital Boston. " It's going to change how the recipe

> turns out. "

>

> One percent may sound small, said. But " it is significant in

> terms of getting another piece of the puzzle solved, " he said, a

> puzzle that has largely stymied researchers even as parents have

> pleaded for answers and cures.

>

> The findings also hold the promise that other hot spots will be

> found, explaining a much larger portion of autism cases. There is

> also hope that studying the genes involved will cast light on what

> goes wrong in autism, possibly leading to new treatments.

>

> The hot-spot paper is the first major publication by a broad new

> Boston group, the Autism Consortium, that brings together families,

> doctors, and researchers to try to crack the complex questions of

> autism. Autism, a spectrum of social and communication disorders

> that usually begin in early childhood, is seen as largely genetic,

> but researchers have not yet found genetic smoking guns.

>

> The collaboration helped speed the hot-spot research and bring it

> quickly into use for genetic diagnoses, said Mark J. Daly of

> Massachusetts General Hospital, the paper's senior author.

>

> " In genetics, it's almost unprecedented to have an initial

> scientific finding so immediately validated in active clinical

> samples and to see relevant diagnostic information fed back to

> clinicians and families, " he said.

>

> Using new, high-resolution gene tests, , working with a team

> at Children's, noticed the hot spot in a few patients a year ago,

he

> said, but he could only tell their parents, " Well, we found

> something, " but " we don't quite know what it means. "

>

> Meanwhile, Daly and his colleagues at Mass. General were using the

> new generation of gene scans on DNA samples from families with

> autistic children nationwide, seeking new genetic culprits. Among

> hundreds of children from that nationwide sample and hundreds more

> who had been tested at Children's, they found mutations in an area

> of Chromosome 16 in about 1 percent of those with autism.

>

> They were able to confirm their findings in the extensive DNA

> samples gathered in recent years in Iceland. Analysis of Icelandic

> samples showed mutations in the hot spot in 1 percent of people

with

> autism; one-tenth of 1 percent in people with different language or

> psychiatric problems; and just one one-hundredth of 1 percent in

the

> general population.

>

> For Morrie and Robin Lewin of Grafton, the hot-spot findings have

> personal relevance. Their 10-year-old twins - iel and Austin,

> who are developmentally delayed - both tested positive for

mutations

> in the key hot-spot area when had their genes tested. At

> first, he could not tell them what that meant; now he can identify

a

> likely factor in their problems.

>

> " For us, it basically means that we now have a diagnosis, " Robin

> Lewin said, " and sometimes that makes it easier when you're trying

> to get services for your child. "

>

> The boys have none of the classic social symptoms of autism, she

> said, but it could help that she can say they have " this new

> chromosomal disorder. "

>

> The findings could also help other parents as they make family-

> planning decisions, said. When parents have one autistic

> child, their chances of having another one are about 5 percent. But

> if testing shows that a parent has the mutation and could thus pass

> it down, the chance of having another autistic child could be as

> high as 50 percent, he said.

>

> More generally, he said, " one of the things parents struggle with

> is, 'Why does my child have autism? Was it something I did? Was it

> something I didn't do?' "

>

> New genetic findings, he said, can help parents know " there really

> was another explanation they had nothing to do with. "

>

> Scientists have no explanation for why such spontaneous mutations

> happen, said , other than that they seem to occur randomly

> during the complex reshuffling of parental genes in earliest

> development and that certain spots are especially susceptible to

it.

> Certain toxins are known to increase the likelihood of spontaneous

> genetic mutations.

>

> The hot-spot paper is extremely well done, said Wigler of

> Cold Spring Harbor Laboratory in New York, who was not involved

with

> it but works on genetic hot spots himself.

>

> Last year, Wigler and his team published a paper boldly predicting

> that, as the resolution of gene scans improves and as more new

> mutations can be detected, they will turn out to explain some 75

> percent of autism cases. " I predict we will find many more new

> mutations causing severe cognitive disorders, " he said.

>

> Carey Goldberg can be reached at goldberg@...

>