From: Joao Magalhaes (jpnitya@skynet.be)
Date: Sat Jul 27 2002 - 10:57:26 MDT
At 14:05 27-07-2002 +1000, Damien wrote:
> >I normally ask three questions to any theory of aging: 1) How to
> >explain Werner's syndrome?
>
>Isn't this (to some extent at least) just a *mimicry* of
>senescence/`aging'? Rather as embryonic unfolding bears an accidental
>resemblance to evolutionary development, giving rise to the mistaken theory
>that ontogeny recapitulates phylogeny. Is it possible that to a large
>extent progeria *doesn't* precapitulate real geria, but just has some
>superficial aspects in common? After all, we don't assume that the baldness
>of little baby boys shares the same root (so to speak) with receding
>hairlines in olde fartes like me.
Baldness of little baby boys is progeria or Hutchinson-Gilford progeroid
syndrome (HGPS), not Werner's syndrome (WS). HGPS is accelerated aging --
e.g. baldness -- in children. The causes of HGPS are unknown. WS appears at
later ages than HGPS. I have never read a case of WS in a baby boy or girl.
On the other hand, I know WS patients can live past 50 years of age.
WS is the hallmark of accelerated aging syndromes since it's the disease
that most closely mimics normal aging. According to George Martin, WS
mimics 50% of normal age-related chances, which is pretty impressive. It's
even more impressive because the normal WS protein is not expressed in all
tissues; the age-related pathologies of WS patients only appear in the
tissues where the WS protein would normally be expressed. Of course that,
since WS does not emulate normal aging with 100% accuracy, it might not be
accelerated aging. Then what is it? Even if WS is not accelerated aging, I
think a theory of aging must explain how a single gene mutation can mimic
50% of age-related changes. Otherwise, you must call WS an exception and we
go back to my reply to Robert about how present theories of aging use too
many exceptions in their arguments to be acceptable.
Best wishes.
Joao Magalhaes (joao.magalhaes@fundp.ac.be)
Website on Aging: http://www.senescence.info
Reason's Triumph: http://www.jpreason.com
This archive was generated by hypermail 2.1.5 : Sat Nov 02 2002 - 09:15:42 MST