I just wanted to say that this has been one of the best threads on this
subject and related subjects in a long, long time.  Thank you Sukie,
Linda and others as this has been a refresher course.  Yes, I've needed
one.  It's been easy to follow as well.  Many times when this subject is
brought up the general message gets lost, bogged down by overly detailed
genetic aspects.
 
I'd like to review some points for readers (and ask others to as well,
because I won't remember it all):
 
-- Selective breeding for fancy markings (obvious neural crest spotting)
should not be done (possibly not for certain colors and dilutes as well
but I suppose that is debatable).
 
-- Breeding practices like this will not just result in probable
deafness, but can also result in other defects such as aortic arch
(cardiac) defects, GI defects (narrowing of the GI track in particular),
limb deformities (such as shortened tail, nubs or none growth related
bumps on the ends of tail, and leg deformities in kits), high kit
mortality, lower number in liters, possible breeding problems (poor
mothering, and sterility?), jaw deformities (shortened jaw, and jaws that
might not open as wide as other ferrets), possible susceptability to
malignacies, and even possible shortened life span (more anectdotal than
scientific).  There may be other associated, but more rarely seen
problems seen in other species such as dulled intelligence, etc, but I
forget what those are.  Of course all or none of which might be present
in a ferret.  Think of it like a collage of possible traits, and each
picture can be different.
 
-- Neural crest disorders are those such as various types of Waardenburg
syndrome (white stripe on the head, possibly pandas, wide set and
sometimes bulging eyes, nasal differences, deafness in 78% of the
animals, other white markings,), KIT (more irregular white markings,
splotchy markings, asymetrical markings ... possibly the panda/blaze
mixes, deafness much of the time, some skull and inner ear differneces,
the list goes on and on), and other less common and studied disorders.
The thinking here is that we are now seeing more possible KIT cases
than WS, or mixed cases in ferrets today.
 
-- These disorders occur when embryo cells (stem cells) are directed
to migrate to various areas to form organs and tissues of the future
organism.  Some of these cells, such as the neural crest cells, go to
Egypt instead of America (lol).  Because of this misdirection there are
defects resulting in various syndromes such as WS.
 
-- Albinos and DEWS can also have neural crest disoders, we just can't
see them because outward markings that would indicate said disorders are
maked by all white fur.
 
-- Expression of neural crest syndomes is extremely variable.  Take a
look at my deaf ferret site to see two complete different expressions.
One ferret looks almost standard ... the other a mixed up "fancy mutt".
 
-- And Melissa is dominant ... no recessive.  Wait.  Darrin is dominant
and Sukie is recessive.  And they all aren't common.  No.  I got it ...
oh hell who cares!
 
-- We as people who "control" breeding of ferrets bear the responsibility
of what we now have have today in the population.  We should breed for
health.  Not for beauty.  Even then we must be careful to not
introducing/increasing new problems in eliminating other problems.
 
-- Not all deafness in ferrets is caused by these genetic problems.
Deafness is also caused by unwise use of Gentamycin (spelling is wrong),
unchecked ear mite infestations, ear infections, neuro infections
(meningitis, etc), and trauma.
 
Okay corrections?  Did I get the basics right?
 
Wolfy
http://wolfysluv.jacksnet.com
[Posted in FML issue 4670]