Jason we have some incredibly smart people who post here, and I am sure you
will get better answers than mine, but here goes.

As I understand it there is a genetic component in this disease, but not in
all cases.   There are so many different kinds of dementia, and so many
different causes, that it isn't so simple as to say that heritage is all of
it.   If I recall there has been some particular gene associated with a
certain kind, but that doesn't mean that if you don't have that gene you
can't still get it.

My father for instance, is 94 years old, and he has vascular insufficiency.
He is a bit forgetful and tends to repeat himself, but it isn't anything
like the alzheimers disease that my mother in law had.    It is a
complicated subject and I suggest that if you suspect a family tendency it
might make sense to investigate further.

This newsgroup is for the most part, concerned with caregiving issues, but
occasionally we get someone who will post scientific discoveries regarding
causes etc.   You could search the archives in Google and I am sure you will
come up with some interesting stuff.

No info re: your request but a thought, having BTDT. If any of the
family approaches the age group where it seems to occur, they might
consider long term health care insurance BEFORE they are officially
diagnosed.

From what I have read, the main type of dementia that has a strong enough
genetic component to be noticeable so far is some types of Early
Onset.(EOAD). Having AZ at age 60 would I believe count as EOAD. However ,
bear in mind that even there its only a slight association, whereas 50%
(yes, a full one half) of all people aged over 85 have Az!

So, the good news is that the mere fact that some old people in your family
have Az is no indication you'll get it...the bad news is that you have 50%
chance of getting it at age 85 anyway :-)  So whilst its common to see
people worry about what actually is a slight genetic association, (and the
only one discovered so far, google EOAD), people dont seem overly concerned
about the 50% chance of getting it even if there is no history in their
family!

re your father, well one person having EOAD means little, unless you know
that your great grandmother had it at say 55 also, in which case the chances
are probably higher..but bear in mind, this is a fairly small risk, and
certainly nothing like the 50% at age 85.

I would hazard a guess chances are the reason the other side of your family
didnt get Az is they didnt live long enough to get to the susceptible age!

Couple of things occur to me. First off, construct as much of a family
tree as you can. going both back and out as far as possible, and
identify what people died of, including at what age they became ill,
and at what age they died. This is an extremely important item to have
with you - when you go and see your doctor.

If there is any kind pattern of people becoming demented/"funny"/crazy
(whatever label might have been put on their problem) at a relatively
young age, your doctor may send you for genetic counselling for
further investigation. Ask as many questions of older relatives as you
can - since early onset dementia was often something families were
ashamed of and hid due to the stigma of insanity. Sometimes a clue is
someone having to leave work young or being "put away".

I went through genetic counselling because of breast cancer in my
family (my mother and grandmother, and one of my grandmother's
sisters). I really had to dig deep to find all the causes of death,
but they really needed that information to help me - and at the end of
the day, they determined that it was fairly certain that it was just
random chance in my family, not the strong genetic predisposition the
carriers of BRCA1 and 2 have.

As Evelyn has said, we all face the 50-50 odds of dementia if we are
lucky enough to live to be 85 or older - but what you are looking for
will be people developing dementia in middle age (i.e. often in that
40-60 range).

You have to keep in mind how poorly investigated and diagnosed many
dementias were in the past. What you fear was Alzheimers in grandma or
great grandma might have been something else entirely - like small
strokes, a vitamin deficiency, hypoxia etc. - there are a lot of
things that can affect cognition in the elderly with an assortment of
health problems, and in years gone by (and even now), doctors often
didn't bother really figuring out the root cause.

Its really informative to KNOW what people died of in your own family
history, since it gives you more solid information about what you may
need to watch with your own health. I'm a hobby genealogist, and my
family is like most - if you ask relatives what was wrong with Uncle
Joe or what Granny Smith died of, you get some pretty vague answers
(i.e. "old age"). Its a lot more useful to know Joe had an aneurism
and Granny got a very rare cancer....so you can answer questions from
your doctor and be proactive about looking out for yourself.

M.

From what you've written, there's no cause to worry until you detect any
symptoms. Even more so,being so younger you have great liklihood that you will
have much better drugs than current sufferers.

In any event, it's liklihood we're all going to die sometime.....

anthony shipley

Run away with me; I can make you unhappy.