Quote:
Originally Posted by canislupus
@Mijke: what do you think about this? I am not experienced with validation of those tests. Is she right? How can we get to know if the test will be really good or if there will be more or less wrong results. (before we have to pay lots of money...)
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Hi Tanja,
For me it is more easier to ex-plain in Dutch! But I ‘ll try to explain it simple in English language.
Personal I think something else is mentioned with
“validation” between the DNA dwarfism test and de DNA HD test.
When genetic specialist are doing research for a genetic mutation it costs years.
I’ll try to explain how it did work with the dwarfism test:
The specialists did start to compare DNA of dwarfs, their parents (= carriers), brothers, sisters with other dogs (which they did know they were free). This research did take years and a lot of blood samples! And in this case the genetic specialist could locate the mutation! And they were lucky that the mutation for dwarfism is “single“ recessive mutation.
(I don’t know the correct translation)
When they did know where to look for this dwarfism gen mutation, they could compare the mutated gen of the GSH with a SWH who was a proven carrier (parent of a dwarf) and then the test was also validated for SWH.
After that I only had to find only 1 CsW dwarf or 1 proven parent of a dwarf to validate the dwarfism test for CsW breed. (because the mutation was "single" already known and theyonlydid have to compare)
But for a DNA HD test it will be maybe more complicated!
Because a lot of genetic specialist expect that HD is not caused by a “single” recessive mutation but will have “multi factor” causes.
Maybe there is not yet found an exact location of a gen mutation. And they have found only the differences in DNA between HD A and HD D/E dogs.
That also explains why they first need 24 CsW’s to see if the differences are the same. And when that is a fact, later on they can compare a lot more CsW’s with and without HD to find the exact differences. And so in future they maybe can find the DNA mutations that causes HD. But that will take a lot of time!!
But maybe I am wrong! So please Ina, correct me when there are other reasons why they need more Csw’s for validation.