Talk:Heritability of autism/archive1

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[edit] "Mendelian" "model"

Hopelessly simplistic, as well as wrongly spelled. Best taken out and a discussion of linkage added, or just a pointer to an article on genetics. Midgley 22:05, 12 April 2006 (UTC)

[edit] Heritabilities

I removed the unjustified weakness on the heritabilities based on my expertise with estimating these. KimvdLinde 15:16, 15 April 2006 (UTC)

[edit] Heritability is only not Autism (causes) if it doesn't include the environmental hypotheses

Otherwise this is just yet another fork/duplicate. Midgley 19:34, 8 July 2006 (UTC)

[edit] Idiopathic autism?

That suggests that there are two (or more) sorts of autism, that caused by specifics and that for whcih no cause is known. Since tehre is no indication that we know a cause for even some autism that seems very like original research. Midgley 19:36, 8 July 2006 (UTC)

[edit] Candidate gene loci

There appears to have been a lot more text here that got thrown out with l33tminion's revision as of 11:38, 7 March 2006 -- probably accidentally. I'm not qualified to determine whether it should be restored to the article, so I'm putting it here for reference. --Collabi 22:17, 16 July 2006 (UTC)

  • SLC25A12

This gene, located in chromosome 2q31, encodes the mitochondrial aspartate/glutamate carrier (AGC1). It has been found to have a significant linkage to autism in some studies [1][2] but linkage was not replicated in others [3].

  • HOXA1 and HOXB1

Dr. Patricia Rodier [4] has identified a link between HOX genes and the development of the embryonic brain stem. In particular, two genes, HOXA1 and HOXB1, in transgenic 'knockout' mice, engineered so that these genes were absent from the genomes of the mice in question, exhibited very specific brain stem developmental differences from the norm, which were directly comparable to the brain stem differences discovered in a human brain stem originating from a diagnosed autistic patient [5].

Conciatori et al (2004) [6] has found an association of HOXA1 with increased head circumference. A number of studies have found no association with autism [7][8][9].

However, the possibility remains open that while single allelic variants of the HOXA1 gene are insufficient alone to trigger the developmental events in the embryo now associated with autistic spectrum conditions, Tischfield et al [10] published a paper which suggests that bexause HOXA1 is implicated in a wide range of developmental mechanisms, a model involving multiple allelic variants of HOXA1 in particular may provide useful insights into the heritability mechanisms involved. Additionally, Ingram et al [11] alighted upon additional possibilities in this arena. Transgenic mouse studies including Rossel & Capecchi [12] indicate that there is redundancy spread across HOX genes that complicate the issue, and that complex interactions between these genes could play a role in determining whether or not a person inheriting the requisite combinations manifests an autistic spectum condition - transgenic mice with mutations in both HOXA1 and HOXB1 exhibit far more profound developmental anomalies than those in which only one of the genes differs from the conserved 'norm'.

Note that in Rodier's original work, teratogens are considered to play a part in addition, and that the possibility remains open for a range of teratogens to interact with the mechanisms controlled by these genes unfavourably (this has already been demonstrated using valproic acid, a known teratogen, in the mouse model).

  • PRKCB1

Philippi et al (2005) [13] has found a strong association between this gene and autism. This is a recent finding that needs to be replicated.

  • FOXP2

The FOXP2 gene is of interest because it is known to be associated with developmental language and speech deficits. An association to autism appears to be elusive, nonetheless [14][15].

  • UBE3A

The UBE3A gene has been associated with Angelman syndrome. Samaco et al (2005) [16] suggests there's reduced expression of UBE3A in autism, as is the case in Rett syndrome. In any case, it appears that the role of UBE3A is limited.

  • Others

There is a large number of other candidate loci which either should be looked at or have been shown to be promising. Several genome-wide scans have been performed identifying markers across many chromosomes [17][18][19]. A few examples of loci that have been studied are the 17q21 region [20], the 3p24-26 locus [21], PTEN [22], 15q11-q13 [23], etc. Other possible candidates include:

  • SLC6A2 (Social phobia)
  • FMR1 (Fragile-X)
  • 5-HT-1Dbeta (OCD)
  • 7q11.23 (William's syndrome, language impairment)
  • 4q34-35, 5q35.2-35.3, 17q25 (Tourette syndrome)
  • 2q24.1-31.1 (Intelligence)
  • 6p25.3-22.3 (Verbal IQ)
  • 22q11.2 (Visio-Spatial IQ)

I'd like to know how come this was thrown out, and why. In the case of the HOXA1 and HOXB1 information I supplied, this is the subject of ongoing research backed by NIH funding in the USA - check the University of Rochester list of current grants for the list of NIH funding entries associated with Dr Rodier's work. I find it strange that research that is the subject of current NIH funding shceduled to continue until 2008 should have been deleted from this article. Can someone explain why? Calilasseia 21:07, 6 September 2006 (UTC)

If there was no edit summary it could be treated as vandalism, essentially. Neurodivergent 22:02, 6 September 2006 (UTC)
I've decided to replace the missing block of text. Epecially as it is replete with references to the relevant pieces of research, and therefore should not have been edited out in the first place. First of all, the block being replaced meets the verifiability critera (enough links to Scientific American and PubMed among others to satisfy even the most nit picking of critics) and it covers important research that is, in the case I've cited above (and almost certainly in the others) the subject of continuing research funded by government bodies such as the NIH in the United States, and the Medical Research Council here in the UK. If anyone wishes to remove it, STATE VALID REASONS FOR REMOVAL. Calilasseia 18:24, 8 September 2006 (UTC)


[edit] Autism text relocation

The Autism article is accruing a lot of material that is more relevant to the theme here and is thus getting very redundant. I have relocated the text here and and I am writing a synopsis there. Malangthon 01:39, 7 March 2007 (UTC)

[edit] Ritvo 1989.

In response to OTRS 2006090110007688, and before finding this page, I found [24]: "Siblings born after one autistic child were 215 times more likely to have autism than siblings of nonautistic children", "The probability of a recurrence in children born after an autistic girl is 14.5 percent, while a recurrence after an autistic boy is 7 percent". Is this now regarded as too high? Was the variant net cast wider? -- Jeandré, 2006-09-05t12:37z

[edit] Please clarify...

This is confusing:

"For example, it would appear that about 40% of diagnosed individuals originally had a 50/50 chance of being considered high functioning. About 4% to 10% had a 50/50 chance of escaping a diagnosis altogether."

At least to the lay person this seems to say that 4% to 10% of those were diagnosed -- were not diagnosed!

(This makes no sense to me.)

There must be a better way to phrase whatever was meant here.

- ef

[edit] "Popular among parents?"

Whoever characterized the thimerosal issue as "popular among parents" should think long and hard about the role of parents in the health of their children. --Leifern 20:25, 5 February 2007 (UTC)