Missing DNA. Children with a missing section of chromosome 17 have distinct facial features and mental retardation. Credit: Sharp et al., Nature Genetics, Advanced Online Publication (2006)
Posted on 08/21/2006 11:28:20 PM PDT by neverdem
Three independent research groups have identified a large genetic deletion that causes mental retardation. "They've broken open a bubble of something that's going to lead to a lot of follow up," comments William Dobyns, a developmental neurogeneticist at the University of Chicago, who was not affiliated with any of the studies.
Mental retardation comes in a baffling diversity of conditions and could be caused by hundreds of underlying genetic triggers, only a few of which have been identified. One glimmer of hope is the advent of detailed scans of individuals' genomes, which are powerful tools in the search for mutations. However, they yield a deluge of data. Focusing in, researchers in the Netherlands, the United Kingdom, and at the University of Washington (UW) in Seattle decided to take aim at "hot spots" on the genome. These regions are flanked by duplicated genetic sequences prone to rearrangement, which can lead to the accidental loss of genes.
Each team examined a different population of people, ranging in size from 50 to 1200, with various kinds of mental retardation. They found that a small number were missing the same six genes on chromosome 17. Two of these genes, when deleted, are thought to be involved with mental retardation. The data suggest that the deletion could be involved in about 1% of all cases of mental retardation, the researchers report online 13 August in a trio of papers in Nature Genetics.
All three teams found these deletions in children, so they decided to check their parents' genomes. The region turned out to be inverted in all the parents. This suggests that the children of parents with inversions are predisposed to the deletion, says Evan Eichler, a human geneticist who led the UW effort.
Although other studies suggest that one out of every five Caucasians of European ancestry may have this inversion, just how many will have children with the deletion is unknown. One problem is the small size of the studies, Eichler notes. To learn more about the deleted genes and their function, scientists need to study more people with the genomic deletion, he says, which is something his team is addressing now.
Related sites
Learn more about mental retardation from Medline Plus
1% is a small percentage.
This still doesn't explain liberals...
Premature Births Linked to Gene Variant
NASA Finds Direct Proof of Dark Matter
FReepmail me if you want on or off my health and science ping list.
Yet it's a start. They should NOT use this to test babies in utero, and then abort them if they do not have these genes. It could be used for gene therapy.
From Medline Plus:
"Mental retardation affects about 1 to 3% of the population."
Out of 6 billion plus total in the world, it's not insubstantial.
They should study the DU'ers.
And if they need more subjects, I'm sure the good folks at the Libertypost would be happy to help.
If I read the article right, it's 1% of the 1%.
With my browser window set at its usual size, I could see the top of the head of the kid in the picture, down to the eyebrows.
Seeing just that much, I presumed it was a picture of Natalie Maines.
"...other studies suggest that one out of every five Caucasians of European ancestry may have this inversion..."
The professional race baiters are going to use this very quickly. Louis Farakhan will be jumping up and down screaming he was right.
The professional race baiters are going to use this very quickly. Louis Farakhan will be jumping up and down screaming he was right.
What's he going to do about other references?
Yes, that's the relative value. In absolute numbers of the world's population of over 6,000,000,000, that means 1% of 60,000,000 to 180,000,000, i.e. the 1 to 3 percent of the world's population that's mentally retarded according to MedlinePlus.
So in absolute terms, it affects over 600,000 to over 1,800,000, notwithstanding "one out of every five Caucasians of European ancestry may have this inversion," however that inversion is related to the actual deletion on chromosome 17.
The last time I looked, the total number of active duty and reserve personnel in the U.S. Armed Forces was about 2,100,000. As the effects of genetics upon health become more understood, I'll wager that you'll find similar numbers.
The three genes cause a predisposition to 1. Beer 2. NASCAR and 3. Big trucks with gun racks. See also: Redneck
:>)
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