The neurofibromatosis type 1.
When we did our
primary brain tumors,
at some point in time, we
looked at a schwannoma.
That schwannoma was arising from
a neurofibromatosis type 2.
And at that time, with that type 2,
I told you to please memorize a particular
gene that it codes for called Merlin.
Here, we have
neurofibromatosis type 1.
The name of the gene
is NF1, neurofibromin.
Incidence: 1 in 3,000.
And the name of the gene or
protein is neurofibromin.
Number one, neurofibromin.
Merlin, type 2.
Those are important.
With neurofibromatosis type 1,
our topic here is
We’re talking about children
is the topic, isn’t it?
These mocha-colored macules that
you might find on the skin –
Mocha-colored, what color is that?
Café au lait spots, axillary freckles,
Lisch nodules or iris hamartomas.
These are important specifically
for neurofibromatosis type 1.
Another name for neurofibromatosis
type 1 is called von Recklinghausen.
Plexiform and simple
neurofibromas, what does that mean?
Now, let me make sure that
we’re clear about this,
is if neurofibromatosis type 1,
once they go into a malignancy,
the name of that cancer
is called neurofibroma.
You can have different
types of neurofibromas.
These may include, I’m giving you
a couple, plexiform and simple.
But really, the point is an -osis,
Obstructive type of hydrocephalus
could be all part of the syndrome
in neurofibromatosis type 1.
And once again, please don’t forget about
it’s called neurofibromin.
Where is neurofibromatosis type 2,
which we’ve talked about already?
Also, autosomal dominant, much less
common than NF1, but you must know it.
Allow the two to speak to you.
And by that, I mean
type 2, two ears,
schwannoma, acoustic neuroma.
What I’m saying is neurofibromatosis
type 2 may give rise to which cancer?
The name of that protein here is
called a schwannomin or Merlin.
Type 2, the chromosome
is 22, Merlin.
Memorize that, please.
With type 2, if it goes
on to cancer, what is it?
There you go.
Bilateral acoustic neuroma,
Multiple meningiomas could
also be a possibility.
Keep that in mind, please.
Genetic testing available for both
types of NF, neurofibromatoses,
and also available for
tuberous sclerosis complex.
What does that mean to you?
At least know hamartin,
and I told you about the skin issues and
tubers and so on and so forth with TSC.
Our topic here is hypotonia.
Reduction of postural.
In other words, a floppy baby.
It may not be associated with
significant weakness by definition.
It could be central or
peripheral in terms of cause .
where you find
hypotonia in a child
Our topic is pediatric
Under hypotonia, if it’s
central in a child,
usually, you’re looking for
associated signs of CNS dysfunction:
seizures, developmental delay,
what does that mean to you?
You’re not reaching a
You keep this separate from
formally known as
If it’s peripheral hypotonia,
lack of central signs.
Weakness is usually prominent,
prominent, here with peripheral.
Here, you might be thinking about
spinal muscular atrophy, SMA.
Peripheral neuropathy, neuromuscular
or perhaps even myopathies.
This is the topic hypotonia
in pediatric population.
The childhood neurodegenerative diseases.
Ones that you want to take a
look at and have differentials.
If you’d notice, macular
you’re thinking about your
Welcome to Tay-Sachs disease.
If it’s sphingomyelin, then
it’s Niemann-Pick disease.
If it’s your
the most common glycogen
storage disease, Gaucher.
It could be found –
Well, macular cherry red spot,
we’d do a funduscopic examination
and you’d find red spot in the retina,
your differentials, are we clear?