WoodHaven
Well-known member
What is frustrating to me is reading posts by people who throw terms around that they don’t fully understand. To say that MRI results are “LOOKS” is the most ridiculous thing I have ever heard. An MRI is a medical procedure designed to find physical abnormalities. To say that the results are “LOOKS” is out and out stupid. An MRI that shows a syrinx is not a “look”, it is an abnormal medical condition that can cause a dog severe pain.
Sandy keeps harping on how two MRI cleared dogs can produce puppies with SM. Since researchers are fairly certain, that SM is caused by recessive genes, of course that is possible IF both dogs are carriers for the gene. Anyone who understands Mendelian modes of inheritance will know that for single recessive genes, if BOTH parents are carriers, EACH offspring has a 25% chance of receiving both recessive genes and will display the trait controlled by those genes. Since the mode of transmission is still not fully understood in SM, we can only postulate from MRI what the chances are of passing on genes to future generations. If the mode of transmission of SM is through recessive gene(s) then if you see a clear MRI (at breeding age), you can postulate that at worst, the dog might be a carrier. When you see you see an abnormal MRI, you can postulate that the dog has both recessive genes and will always pass on the defective gene.
I work with children who have disabiliities. I work with families who have genetic defects. I have worked with families that have never had the genetic trait show up in their families only to have two or three of their children affected. I see families where both parents and children have the same syndrome. Even within families, the expression of the gene can vary from individual to individual. Genetics is a very complex subject. I have taken doctorate level courses in genetics. Some genes turn on at birth, others may turn on at different ages, some may need an external event to turn on. Right now, it still is not understood what causes the SM gene to express itself.
Then you should be advocating that breeders test the same as you do. The only way that researchers are going to find the gene(s) responsible for SM is for responsible breeders to test and share their results with the researchers. There should be no shame in producing a dog affected by SM IF the breeder has done everything in their power to prevent it. The shame comes when breeders don’t use the tools available to study SM and possibly find the genes responsible. Then maybe breeders will have the better tools available to combat this condition.
J.
Wow Jay -- and the other board is considered "NASTY"? WTH have I ever done to you??
First of all, sigh, an MRI is a group of pictures-- how phenotypical can you get? genotype plus environment gives you what you see (referred to as phenotype). Discussed this with a neuro who taught neurosurgery. BUT if you Know better, I stand corrected. I am here to learn too.
I've seen MRI's of dogs that were horrendous -- you wonder how the dog can breath-- but they showed no/little signs of illness. I have heard of dogs in terrible pain, that have beautiful MRI's. So yes, an MRI is a picture of how a dog LOOKS.
Well, last time I looked they weren't sure it was caused by recessive genes. It was assumed because dogs WITH SM could have pups without that it must be. But Dutch based research has pointed out that this may not be so. They were discussing Autosomal dominance and incomplete penetrance and I will be honest, I didn't pay attention to ALL the details-- My mind went-- The experts aren't sure either. One thing is for sure-- this isn't going to be as easy as fruit flies or flowers.
J-- IF I KNEW that my way was the right way, yes, then I would be jumping up and down.