Alzheimers Question

wijsman at wijsman at
Wed Dec 4 13:18:09 EST 1996

> Pure grandmother (now deceased) was born in 1900.  At or
> around 1981-82 when she was getting a bit fuzzy-minded, her doctor said
> that she was "too old" to have alzheimers.  Huh?  I didn't know that the
> disease precluded people born before a certain year...what did he mean or
> was he just incompetent?

The original definition of Alzheimer's disease required early-onset.  Now,
because there is no clinical difference between early & late onset, this
distinction is no longer made for a clinical diagnosis (i.e., a person CAN have
AD at age 80).  This shift in the definition occurred more towards the end of
the 1980's; I think in 1980, the definition of AD still required early onset (so
the Dr. was providing current-for-the-time advice). In the past few years, 3
genes have been identified in which mutations cause early onset, inherited AD,
but not late onset AD.  Thus we now know that the etiology of early vs. late
onset AD (defined quite arbitrarily) IS different, even if the resulting
phenotype is the same.  So in some sense we are back to the beginning -
Alzheimer was right in that early onset dementia was etiologically different
that late onset dementia, but even early onset AD has multiple causes, and since
the clinical  course so far does not seem to be a function of the specific
mutation, AD currently is considered to be something which can occur from
mid-life on up, with multiple underlying causes, some known & some unknown.

Ellen Wijsman
Research Associate Professor
Div of Medical Genetics, BOX 357720
and Dept of Biostatistics
University of Washington
Seattle, WA   98195
wijsman at

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