Here's three important late onset disorders, two,
two neurologically degenerative disorders, Parkinson and Alzheimer disease.
And the third is age related Macular Degeneration.
In the case of Parkinson and Alzheimer disease, the,
the investigators reported that concordances from monozygotic,
which is in blue, and dizygotic, which is in red, they reported them separately for
men and women, and they did not do that with respect to Macular Degeneration.
The results don't look that different between the men and the women,
so I won't comment on those.
But do we see the same general pattern that we saw in earlier life?
Of course we only have three disorders here, so
it's hard to draw real strong conclusions.
But I think one of the things that, to me at least that's striking about research in
this area is that there seems to be quite a diversity of genetic influence here.
For something like Alzheimer disease the genetic influence
appears to be rather strong.
For Parkinson disease in contrast,
the genetic influence, if there is one, seems to be rather weak and
Macular Degeneration appears to be somewhere in between the two.
And indeed if we did a biometric, or these investigators that published these
studies did do a biometric analysis of these concordance rates.
What they report is given here and
is consistent with that characterization I just gave you,
that it appears that Alzheimer disease, Alzheimer dementia is highly heritable.
Parkinson's disease is at best weakly heritable.
The heritability estimate here only being on an order of about 10%, where as macular
degener, age related Macular Degeneration is somewhere intermediate between the two.
[SOUND] The third question,
to what extent do genetic factors contribute to how we age?
Well, before we can answer that question we have to define what we mean by age.
How do we measure how we age?
And how we go about doing a study to investigate how we age?