Page 4 of 5 FirstFirst ... 2345 LastLast
Results 46 to 60 of 75

Thread: DNA test for scoliosis

  1. #46
    Join Date
    Jan 2008
    Location
    NC
    Posts
    9,173
    Quote Originally Posted by PNUTTRO View Post
    I think you're right about that being too high. Especially since siblings only share on average 50% of the same genetic information.
    But this observation is consistent with the germ theory of scoliosis, yes?

    Spine (Phila Pa 1976). 1997 Sep 1;22(17):2009-14; discussion 2015.
    Scoliosis in twins. A meta-analysis of the literature and report of six cases.

    Kesling KL, Reinker KA.
    I'd like folks to try to imagine this paper being written on self-reported zygosity and scoliosis. Just try. The hew and cry would be deafening.

    Very clearly the only reason the Danish study made it to print is the large cohort. But by their own numbers, we know those data are flawed.

    I don't think most folks realize the sheer volume of specious reasons out there that parents deny identicalness. Read the "reasoning" the Olsen twins give on their web page. Stem to stern nonsense... ignorance on the wing. My twins differ in all those respects and then some and they are without a doubt identical (one chorion).
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  2. #47
    Join Date
    Jan 2008
    Location
    NC
    Posts
    9,173
    From the Danish Twins study...

    1. self reporting of zygosity and scolisois status, both with known bad track records for accuracy in self reports.

    2. problematic data selection:

    A total of 34,944 (75.3%) representing 23,204 pairs returned the questionnaire. RESULTS: A subgroup of 220 subjects considered to have AIS was identified, thus giving a prevalence of 1.05%.
    Based on responses to a survey by the (untrained) subjects, the researchers made a further decision about whether these 220 in fact did have scoliosis. The incidence of scoliosis (1%) is a clue that they are missing at least half and possibly 2/3 of the scoliosis cases, perhaps the milder ones. This is no small omission.

    The concordant twin pairs were all monozygotic. Pairwise, the concordance rate was 0.13 for monozygotic and zero for dizygotic twin pairs; proband-wise concordance was 0.25 for monozygotic and zero for dizygotic pairs.
    Zero for fraternal twins? Doesn't that completely undermine the germ theory of scoliosis?

    I would hope the full text also includes the number of mono and di pairs. These subjects were born before 1982 (before in vitro fertilization took off) and that ratio is well know. If the self reports don't match that ratio then we know almost for a fact the (self-reported) zygosity is wrong given how large the sample size is.

    I haven't seen this paper but my guess is the number of identicals is extremely underestimated in these self reports. And we know the incidence of scoliosis is underestimated by half to two-thirds. I don't know what others think GIGO is but this paper falls into that definition for me.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  3. #48
    Join Date
    Apr 2009
    Posts
    1,258
    Interested in what Sharon may gleen from this one:

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2148088/

    ABSTRACT

    Treating children with idiopathic scoliosis can amaze someone at the many different ways in which the deformity can present. Most authors state that genetics stipulates the course of adolescent idiopathic scoliosis. This is mainly based on the high concordance in monozygotic twins. However, there is indication that environmental factors have influences on adolescent idiopathic scoliosis. This is the first report in which a monozygotic twin pair is described concordant for idiopathic scoliosis but with different apical levels, magnitudes and age at detection of scoliosis which stresses the importance of environmental factors.

  4. #49
    Join Date
    Mar 2009
    Location
    Arizona
    Posts
    1,058

    62.5%

    Pooka1

    But this observation is consistent with the germ theory of scoliosis, yes?
    Brothers and sisters share 50% of their DNA so a 62.5% concordance rate would indicate environment.

    However life experience makes it pretty obvious that Scoliosis isn't 62.5% concordant among siblings. I doubt it's even that high among identical twins.

    A small percentage of families are hit very hard by Scoliosis but it strikes most kids seemingly out of nowhere.
    Last edited by Dingo; 11-16-2009 at 07:42 AM.

  5. #50
    Join Date
    Jan 2008
    Location
    NC
    Posts
    9,173
    Quote Originally Posted by mamamax View Post
    Interested in what Sharon may gleen from this one:

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2148088/

    ABSTRACT

    Treating children with idiopathic scoliosis can amaze someone at the many different ways in which the deformity can present. Most authors state that genetics stipulates the course of adolescent idiopathic scoliosis. This is mainly based on the high concordance in monozygotic twins. However, there is indication that environmental factors have influences on adolescent idiopathic scoliosis. This is the first report in which a monozygotic twin pair is described concordant for idiopathic scoliosis but with different apical levels, magnitudes and age at detection of scoliosis which stresses the importance of environmental factors.
    That's a pretty interesting article!

    I mentioned everal months ago how researchers were finding differences that were much more than expected between monozogotic twins and epigenetic changes were suggested as a likely cause of the differences. This paper is consistent with that.

    Last, I think until they start rigorously identifying the connective tissue disorder patients within the AIS population, the data will be muddied.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  6. #51
    Join Date
    Mar 2009
    Location
    Arizona
    Posts
    1,058

    twin studies

    I should add one thing. Just because a twin study finds that a particular disorder is 25%, 50% or 75% concordant doesn't mean it is 25%, 50% or 75% genetic.

    Leprosy is caused by a bacterial infection that can be cured with antibiotics. Depending on the study identical twins are 60% to 80% concordant.

    Like so many other diseases genes create susceptability to a particular type of environmental damage. Because twins share the same genetic susceptability and live in the same home if one succumbs it's very likely that the other will too.
    Last edited by Dingo; 11-16-2009 at 04:51 PM.

  7. #52
    Join Date
    Jan 2008
    Location
    NC
    Posts
    9,173
    No I don't think anyone is interpreting the concordance between identical twins in isolation apart from a cohort of fraternal twins.

    Looking at only identical, it is impossible to say what is genetic, epigenetic, and environmental.

    It is only when the comparison is made to fraternals that there is any hope of making a conclusion unless they otherwise know something is under genetic control and they can then look for epigenetic differences and things like that. But you can't answer the primary question of etiology just by looking at either identicals or fraternals.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  8. #53
    Join Date
    Mar 2009
    Location
    Arizona
    Posts
    1,058

    2 out of 3

    Pooka1

    The fact that 2 out of 3 children with severe Scoliosis have no 1st, 2nd or 3rd degree relatives with any known spinal disorder says more about the genetics of Scoliosis than any twin study so far.

    Melatonin Signaling Dysfunction in Adolescent Idiopathic Scoliosis (scroll to page 2 for the table)
    Last edited by Dingo; 11-16-2009 at 05:02 PM.

  9. #54
    Join Date
    Jan 2008
    Location
    NC
    Posts
    9,173
    I do NOT consider that a fact. We have some evidence (Danish Twins Study) that at least half and perhaps 2/3 of scoliosis cases are missed in self reports. It is very likely that most, a majority of cases are missed unless they become obviously surgical which we know is only a small percentage of total cases.

    On this group alone and just in the last several months there are a few kids who presented with a vary large curve.

    It is thus IMPOSSIBLE to say that "2 out of 3 children with severe Scoliosis have no 1st, 2nd or 3rd degree relatives with any known spinal disorder" is anything close to fact.

    Rather is remains unknown what percentage of these kids have a relative (1st, 2dn or 3rd degree) with scoliosis. For all we know, it may approach 100%. We simply don't know.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  10. #55
    Join Date
    Mar 2009
    Location
    Arizona
    Posts
    1,058

    2 out of 3

    Pooka1

    For all we know, it may approach 100%. We simply don't know.
    If Scoliosis was caused by heredity and these were the most genetically susceptible children the number would be 100%, or close to it. Severe Scoliosis should be well represented throughout most of these families.
    Last edited by Dingo; 11-16-2009 at 05:33 PM.

  11. #56
    Join Date
    Jan 2008
    Location
    NC
    Posts
    9,173
    No there are plenty of cases where the severity differs within a family. Just because there is one bad case doesn't mean there can't be many other mild cases in the immediate and extended family.

    Unless you radiograph all the relatives, you can't know. That statement is obviously unknowable and likely false.

    Just read some testimonials and signatures on this site.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  12. #57
    Join Date
    Mar 2009
    Location
    Arizona
    Posts
    1,058

    62.5%

    Pooka1

    If Scoliosis was caused by heredity and it was 62.5% concordant among siblings (Idiopathic Scoliosis in twins) what do you think these families and extended families would look like?

    Scoliosis of all degrees from severe to mild should be everywhere.

  13. #58
    Join Date
    Jan 2008
    Location
    NC
    Posts
    9,173
    Quote Originally Posted by Dingo View Post
    Pooka1

    If Scoliosis was caused by heredity and it was 62.5% concordant among siblings (Idiopathic Scoliosis in twins) what do you think these families and extended families would look like?

    Scoliosis of all degrees from severe to mild should be everywhere.
    Scoliosis should be fairly prevalent in these families and we don't know that it isn't. We know that most cases are NOT severe and never make it to surgical territory. That fact strongly suggests most cases will be mild and therefore easily missed. Even some surgical cases are missed when there is no pain and not much rotation. Again, the Danish Twins study had at least one result.... self reporting is known to miss at least half adn likely 2/3 of scoliosises. This is all consistent.

    What is the evidence for the statement: "2 out of 3 children with severe Scoliosis have no 1st, 2nd or 3rd degree relatives with any known spinal disorder." Unless they radiographed every single one of these degree relatives, they can't know that. And we know they didn't radiograph all these people.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  14. #59
    Join Date
    Mar 2009
    Location
    Arizona
    Posts
    1,058

    prevalent

    Pooka1

    Scoliosis should be fairly prevalent in these families and we don't know that it isn't.
    I guess time will tell but personally I'm betting on Dr. Moreau.

  15. #60
    Join Date
    Mar 2009
    Location
    Arizona
    Posts
    1,058

    Scoliosis screenings

    Pooka1

    Dontcha think that the siblings of children who underwent spinal fusion would also be screened for Scoliosis? If Scoliosis was caused by heredity (say 62.5% concordant) it would be all over the place.

    Your worldview that most parents are not aware of the health of their other children or extended family is not credible.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •