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My name's John Hardy.
I work at the Institute of Neurology
at University College London.
What I'm going to talk
to you today about
is the genetics of
This is either the second or the
third most common form of dementia
after Alzheimer's disease, and
afflicting about the same number
of people who have
dementia with Lewy bodies.
It's a devastating disease, as
I'll explain later, and really
a major public health
problem and, of course,
social problem for those people
who are afflicted with the disease.
The characteristics of
are that the frontal and
temporal lobes of the brain
are affected and show gross atrophy.
It's responsible for about
10% of all dementias,
and depending on the survey, affects
somewhere of the order of 3 to 15
every 100,000 individuals.
The reason there is
this type of variability
is because sometimes the diagnosis
is rather difficult to make
and because it can sometimes
resemble Alzheimer's disease.
Unless there is
then prevalence rates can vary based
upon the diagnostic criteria which
The onset age for the
disease is typically
in the late 50s or early 60s of age.
I do know of cases where the
onset age is from the 30s.
And of course, it can afflict
people in their 70s and 80s.
But the typical ages of onset are,
as I say, in the 50s and the 60s.
High proportion, about a quarter
of the cases, are familial.
That means usually that people
in the familial category
have one of their parents
who have had the disease.
And of course, the grandparent
on that side of the family
can also have been afflicted.
So sometimes, you
can see the disease
traveling down through
It's a very variable disease in
terms of its clinical presentation.
Some people have language problems
very early in the disease.
They have difficulty speaking.
They become what is known as
aphasic, and they can't find words.
Other individuals have
very early in the disease process.
And they can become either
apathetic or rather disinhibited.
A very frequent
complaint of caregivers
is that their loved one seems as
if they're drunk in their behavior.
They either become very
quiet and almost mute,
or they become very
inappropriate in social settings.
In agreement with this
there is actually a lot of
So I've described how the disease
is characterized by atrophy
of the frontal lobes or the
temporal lobes of the brain.
But the histopathology-- that means
the pathology in the brain cells--
is also variable.
And to some extent,
though not perfectly,
this pathological variability fits
with what I'm going to tell you
about the genetic heterogeneity
and also fits to some extent
with the clinical
heterogeneity, as well.