In a recent thread on my blog, I got a comment from Dr Jim Laidler in response to AFF's own Bonnie Ventura. I thought uoi might all want to have a read.
http://www.kevinleitch.co.uk/wp/index.ph...mment-1962
He says:
I have long been suspicious of anyone who claims to have a genetic test for autism – or even to have found “the autism gene”. Autism is too varied and variable to be either a single-gene disorder or, perhaps, even a single disorder at all.
To give you some idea of the magnitude of the problem of developing a genetic test for autism (prenatal or otherwise), I refer you to the following paper:
Yonan, et al. “A Genomewide Screen of 345 Families for Autism-Susceptibility Loci” (Am. J. Hum. Genet., 73:886-897, 2003 –
http://www.journals.uchicago.edu/AJHG/jo...40053.html )
In this study, they found that a screen of 345 families for potentially autism-related genes netted “hits” on chromosomes 1, 2, 3, 4, 5, 6, 7, 10, 11, 17, 19 and X (12 out of 24 – counting X and Y as separate chromosomes). The biggest hit was on chromosome 17, which has long been thought to be an autism “hotspot”, but there were families that did not show a connection to chromosome 17. So,
I wouldn’t worry too much yet about a genetic test for autism.
What might come out of all this genetic study is a better understanding of how many disorders make up the entity we call “autism” and what it is that causes the abnormalities seen. That alone would be more than enough to justify the effort and expense.
Jim Laidler is a Doctor who himself is the parent of an autistic child. He runs the site http://www.autism-watch.org/ which exposes a lot of scientific quackery regarding autism. I've conversed with him a number of times and I know he's on equally chatty terms with Kathleen Seidel and the Autism Diva. He's definitely one of the good guys and someone very well qualified to know what he's talking about.
Amy- although tests for Down's are generally not extremely accurate in showing that the fetus has Down Syndrome, at the amnioscenesis level, the mistake is usually that they mistake Down's for another serious disorder, and not for a typical child.
I'd like to point out my great scepticism at this 90% of Down's babies are aborted claim - the more I think about it the more it sounds like something that Precious Life might make up.
I have looked through the Down's Syndrome Society's home page BTW and there is no mention of this anywhere. They are pretty strong on the rights of people with Downs Syndrome, and I suspect would discuss it if it was an issue.
This is what I thought - it is 90% of those who are prenatally tested, and the only reason why a woman would want to have a prenatal test for Downs is if she didn't want to have a baby with Downs! The Downs Syndrome Society states on its website that around 600 babies are born each year with Downs, and that it is likely to occur in 1 in 1000 babies. This appears to suggest statistically that the babies being aborted are very small - just think about it for a sec. If 600 Downs kids are born each year, and none were being aborted, that would mean approx 600,000 babies are born in the UK each year, which sounds like a plausible figure for the annual number of births (unless someone knows anything different).
So all this suggests that, unless one believes that aborting *individual* Downs babies is an issue (which being pro-choice I don't) then there is no issue here. And similarly this makes me doubt claims that a prenatal test for autism will lead to genocide - if it hasn't for Downs Syndrome then its not likely to for autism either.
They may also have the test to be prepared. I know I don't like surprises and like to be prepared. I can't remember if I got a test or not but I would have if it was not invasive or dangerous--just to know, not to abort. A lot of women get amniocentisis which in itself is a miscarriage risk and may be very stressful for the baby (babies photographed flinching away from the needle or batting at it) just to find out, which I don't personally agree is worth the risk, although a friend who carried a severely _____ baby (can't think of a word) who died at birth got one for the next baby because she just had to know the condition of her baby and not worry the entire pregancy (bad for baby, too).
As to the statistics for Downs, they go up as the woman gets older. A 25 year old has a 1 in 1250 chance to give birth to a DS baby, a 40 year old has a 1 in 106 chance. With more women giving birth at older ages, I wonder where these (statistical) babies are? Not that I hang my hat on statistics, after all, there was a .05 chance that the disaster in New Orleans would happen (which is why they didn't spend the $$ to fix the levees).
Why does Jim Laidler say: "Mental Retardation. Many children with ASD have some degree of mental impairment. When tested, some areas of the brain may be normal, while others may be especially weak. For example, a child with ASD may do well on the parts of the test that measure visual skills but earn low scores on the language subtests."
Is his description after the words 'Mental Retardation' actually a description of mental retardation? Am I quibbling with words--is this just a denotation? But the connotation is so bad and the average person reading it will understand only the connotation.
I've e-mailed the Downs Syndrome Society and am awaiting a response - much better than arguing the toss about this, which could go on forever.
BTW it was me e-mailing about Jodrell Bank just now. Sorry I forgot to sign in.
I dont think it will never happen.. just that it is unlikely to happen soon, and if it DOES happen soon it will not be a very accurate test. With so many opinions from different researchers (in this forum alone I see ten years, five years, and 'not soon') it is difficult to be sure.
BUT in my judgement (admittedly that of only a first year cell biology & neuroscience major) it seems unlikely that any prenatal tests will be developed soon with any real accuracy. It would be like trying to predict the outcome of a presidential election going by each candidate's home state. The information available is thinly spread, often contradictory, and the ways in which each factor actually affects ASD susceptibility is rather poorly understood.
OK... Where are the pro-life groups you mentioned getting this? Did they say where they got that information? Because I dont necessarily trust their word, they are by definition political organizations, and any scientific evidence they offer is suspect in my book.
More to the point, downs syndrome is a bad example because its an entirely different kind of disorder. For one thing, someone either has downs syndrome or they dont. Theres a pretty clear dividing line. ASDs on the other hand can be confused with all sorts of things. Downs syndrome is not a condition of genes, rather its a aneuploidy, or a chromosomal disorder. It is determined by the presence or absence of a single defect, whereas autism cannot be tied down to any one polymorphism, or even any 2 or 3 polymorphisms.
In conclusion the two are far too different to compare them with respect to ease of genetic testing. As I have said before, ASDs are genetically complex, meaning they are WAY WAY WAY WAY WAY more difficult to develop tests for. Forget needles in a haystack, its like trying to find ten dozen needles in a dozen haystacks and then figure out which combination of those needles makes the best sewing kit.
Anyway, its REALLY hard. Its so incredibly complex the only way to do it is through trial and error. Emphasis on the error.
As to Stella's comment, while certain groups might be liable to try a eugenics program, its not fair to ascribe similar ambitions to the researchers. Most if not all of them are probably researching it to learn more about the way the brain works. The CAN-ites are the ones spewing eugenicist ideas, not the researchers.
Who said anything about listening to the government?
I dont know about the government on the other side of the ocean, but anything THIS government says about science I assume to be 180 degrees opposite the truth until proven otherwise. This government has a history of twisting and manufacturing science to serve its political needs. Political organizations are like that.
I dont pay much heed to ANY statistics that come from a politically motivated group. As you say, a political group may have access to facts, but what facts they REPORT may not accurately reflect the actual research consensus. If 10 studies say they are wrong, and one says they are right, they may well put the one on their website and leave the rest by the wayside. Thats politics.
It is difficult to know how many babies are being aborted due to results of prenatal genetic testing. I am not sure that anyone is collecting statistics or even if they legally able to get that information.
In that case I suggest you pay attention to the actual recorder statistics and compare them to what the pro-life group in question says. I suspect you'll find a few discrepancies... Nothing outright manufactured, but some data emphasized over other data.
Well in that case youre rather a bit better off in that respect than us over here in the US...