Researchers at Cold Spring Harbor published a study on this in April. Below is the abstract. It's written in scientific jargon, but I think I understand what it's saying. The main points are:
1. They were looking at copy number variants (CNVs) in autistics with and without family history of autism plus non-autistics. They compared these to the parents' genes so they could see which CNVs were new (de novo) and which they had inherited from their parents.
2. They found new/de novo CNVs in only 1% of the nonautistic subjects, in 3% of the autistic subjects who had a family history of autism, but in a whopping 10% of the autistic subjects with no family history of autism. This is a significant finding, but they're a long way from figuring out the details of which CNVs might cause autism, and how it works.
3. These aren't big genetic variants like Down syndrome which involves an extra chromosome that's easy to see. Rather, this research was looking at CNVs that were "smaller than microscopic resolution." There wasn't any particular consistency in which region the affected genes were located, and sometimes it was just a single gene that was mutated. This seems to fit with the findings on your son's test, but I'm just a layman.
"We tested the hypothesis that de novo copy number variation (CNV) is associated with autism spectrum disorders (ASDs). We performed comparative genomic hybridization (CGH) on the genomic DNA of patients and unaffected subjects to detect copy number variants not present in their respective parents. Candidate genomic regions were validated by higher-resolution CGH, paternity testing, cytogenetics, fluorescence in situ hybridization, and microsatellite genotyping. Confirmed de novo CNVs were significantly associated with autism (P = 0.0005). Such CNVs were identified in 12 out of 118 (10%) of patients with sporadic autism, in 2 out of 77 (3%) of patients with an affected first-degree relative, and in 2 out of 196 (1%) of controls. Most de novo CNVs were smaller than microscopic resolution. Affected genomic regions were highly heterogeneous and included mutations of single genes. These findings establish de novo germline mutation as a more significant risk factor for ASD than previously recognized."
http://adsabs.harvard.edu/abs/2007Sci...316..445S
I recently posted an interview with one of the researchers at Cold Spring Harbor, which you might find interesting. And it's in plain English -- thank goodness! Here's the link:
http://www.autism-pdd.net/forum/forum_posts.asp?TID=19365&am p;KW=cold+spring+harbor
Good luck with everything.
On which chromosome? Any more specifics given?HEY FAITHISHOPE--- Just for curiosity I have ton ask if you know about Smith-Magenis Syndrome? My son was diagnosed from age 7n with PDD/NOS. then we met a family with a child exactly like mine. To make a lonnnnng story short,we went to a geneticist who did a "FSH" test.(we say fish test in SMS talk)this test finds a deletion on the 17th chromosome. This is what we call "SMS". It is considered rare,but really because it is underdiagnosed. If you would like more info please go to www.prisms.org and look over some of the characteristics and see what you think. If its not your child always remember it because I guarantee you will hear more about it in years to come. I am always on a soapbox about it because we should have NEVER had to go as long as we did without a proper diagnosis. We met kids and adults at the last conference in May in D.C. who were 20-30 years old and had only had a diagnosis 4-8 years!! Imagine that!! I would love to hear back from you and my "door " is always open!! Hope I shed some light!The results specifically say that the variance is too small to be picked up by the "FSH" or FISH test, but here is what it does say.
Variant of unknown significance
Type of Change: deletion
Chromosome band/region: 2p12
Chromosome coordinates: 79,116,437-79,365,507 (human genome build:hg 17)
Size: 249 kb
Clinical comments: this array of CGH contains coverage for targeted regions of the genome. No deletions or duplications were identified in the targetes regions. The array also covers areas outside the targeted regions. The copy number changes identified in thes pationt li outside the targeted region. There is no evidence to suggest that this copy numbervariant (CNV) is clinically relevant, but this possibility cannot be excluded. This CNV has not been reported in currently available literature/database resources. The genes within the CNV are not listed in OMIM as being associated with any known syndrome. Most (95%) CNV's are less than 500kb, and most CNV's are not known to cause a disease, so this may be a benign variant.
Phew!
Robyn, does the new DX change anything? Does it change the course of action? I honestly do not care what the DX is called as long as he gets what he needs to succeed. I will take a look at the site you listed. Although, knowing this variance would not have shown up on the FISH makes me believe it is not it.
You have some genes that are different than the rest of the population? Is that what they are saying?We just had our Neuro follow up and all went well. He said he could tell that the therapies were going well and he could see no reason for great progress not to coninue
On the other hand...on our first visit we had the full DNA and genetic testing done for DS. I was absolutely SURE that it would show nothing. Well
They want both my DH and I to be tested, more for research than anything (for free). This is a major coastal city Childrens Hospital, with a lot of Autism research going on. Particularly with genetics. We have already participated in 2 genetic studies (non-invasive) since his DX in early June.
Anyway, any thoughts would be great, and if this peaks anyones interest, I will type verbatim what the report says (in whatever genetics language it is in
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