[elf]

Originally Posted by nanouk

I have been told this many times, also with regards to Saarloos.. With the many dogs that will never show the illness, can you name me 1, just one 'affected' TWD age 10 or older that doesn't show signs?
I hope i assume correctly that with twd like with the SWD 10 is not "old" yet.

Another interesting part from publication Genome-wide association analysis reveals a SOD1 mutation in canine degenerative myelopathy that resembles amyotrophic lateral sclerosis

"Mode of Inheritance of DM. All of the strictly diagnosed DMaffected
dogs were A/A homozygotes; however, several of the
aged A/A homozygotes were symptom free. Thus, DM appears
to be an incompletely penetrant autosomal recessive disease,
whereas most human SOD1 mutations cause dominant forms of
ALS. However, the N90A SOD1 isoform is associated with a
recessively inherited form of ALS in some families, but with a
dominant form in others (29, 30). The natural history of the
disease in the families with recessive inheritance resembles
canine DM in that onset is invariably in the lower limbs followed
by a slow disease progression, whereas the sites of onset and the
rates of progression of ALS in heterozygous N90A patients are
much more variable (29, 30). Among the families segregating for
the dominant form of ALS, rare patients with 2 copies of the
mutant SOD1 allele had much earlier ages at disease onset than
patients inheriting only a single copy (31, 32). Also, hSOD1m
mice with higher transgene copy numbers exhibit earlier disease
onset (5, 33), and the disease also occurs much earlier in
homozygous hSOD1m mice than in the corresponding heterozygotes
(34). With DM, the intermediate levels of staining for
SOD1 inclusions observed in 2 of the 5 aged heterozygotes (Fig.
3 E and F) suggests that pathological processes are underway in
these dogs even though no clinical signs are apparent. The
pathology in SOD1:c.118GA heterozygotes may develop too
slowly to become clinically apparent within the usual canine life
span. In this case, only A/A homozygotes would exhibit clinical
signs and the mode of inheritance would appear to be recessive
even if the pathogenesis, like that of ALS, involves a toxic gain
of function."

In addition, hypothesis dogs (N/DM) might be developping the disease (commonly much later, and more rare cases), so unfortunately we are still far to understand.