Leucism is not the same as neural crest defects but can include some
forms of neural crest defects as causes of leucism though there are
also other causes of leucism which is hypopigmentation. Hypo means
"below" (like in hypodermic which means below the skin) or "less" (like
in hypothermic which means cooler than the body is supposed to be, so
less heat) and pigmentation is coloring.

Okay, I will make it short and sweet -- only the basics. The embryo in
the beginning is only a clump of cells that are all the same. Those are
stem cells. There are not organs, and the shape is just a clump. The
next shape once there are enough cells looks like a soccer ball and is
hollow like one, too. There are still no organs. Eventually, there are
more cells but still no organs.

Once there are enough cells they start to have some differences (again,
no organs and no human shape yet). The different areas are called
"crests". The cells then are no longer true stem cells because they
can not grow into absolutely anything.

One of the earliest crests in the cardiac neural crest:
http://en.wikipedia.org/wiki/Cardiac_neural_crest_complex and like
it sounds, the cells from that will create things like the heart and
nerves but also a lot more, including pigment cells and part of the
structure of the jaw and ears.

Later the cardiac neural crest differentiates into two crests: the
cardiac crest and the neural crest. The neural crest controls the
formation of many things so when you have a mutation there a wide range
of things can go wrong in many parts of the body: the individual may
be deaf or partly deaf, the nerves for the GI tract may be wrong which
creates a lot of problems down the line, the jaw may not work properly,
cardiomyopathy rates are increased (which is thought to perhaps be due
to damage to the sympathetic nervous system), and other things can also
go wrong at higher rates than for individuals who do not have those
genetic variations. Here is the wikipedia section on it:
http://en.wikipedia.org/wiki/Neural_crest

Yes, it is a somewhat complicated topic, but ferret people get used
to complicated topics. Heck, we have animals who are prone to
endocrinological diseases like adrenal disease and insulinoma, so
we have to get used to complex issues. Never thought you'd wind up
learning so much biology just from loving a weasel, right? LOL!

Sukie (not a vet)

Recommended ferret health links:
http://pets.groups.yahoo.com/group/ferrethealth/
http://ferrethealth.org/archive/
http://www.afip.org/ferrets/index.html
http://www.miamiferret.org/
http://www.ferrethealth.msu.edu/
http://www.ferretcongress.org/
http://www.trifl.org/index.shtml
http://homepage.mac.com/sukie/sukiesferretlinks.html
all ferret topics:
http://listserv.ferretmailinglist.org/archives/ferret-search.html
"All hail the procrastinators for they shall rule the world tomorrow."
(2010, Steve Crandall)
On change for its own sake: "You can go really fast if you just jump
off the cliff." (2010, Steve Crandall)

[Posted in FML 7095]