Crytorchidism inheritance research - Page 1

I had been doing some research on Crytorchidism (unilateral and bilateral). Genetics and inherited traits happens to be a fascination of mine. I'd been tracing litters from various dogs that had puppies suffering this condition, and I have noticed that it seems to be as often carried by the dam as by the sire.

Obviously, only male pups suffer the condition; but it appears to be carried on the x-chromosome, not the y. One of the females I had been observing produced at least one Crytorchid male per litter, regardless of the male she was bred to. I noticed this with other females I'd been observing.

I was wondering if there was anyone who could point me in the direction of finding documentation on this in-depth; or knew of any studies like this previously done to determine the possibility of Crytorchidism being something that can be passed down through maternal as well as paternal lines.

I'm now quite convinced that the dam is as much a contributer for this condition as the sire.



I am also currently looking to see if it's something that needs to be carried in both parents before it can be expressed in a litter, or if it can be passed on and expressed even if only one parent carries it. For this I need to observe the progeny of a normal dog with Crytorchid full-sibling... and needless to say this is where I start running into problems because of the sheer number of dogs I've been trying to track and sort through; and the generations I have to follow (minimum of 3).

Again, if anyone has any info or leads that could help, please feel free to contribute.

I have read (article by Lanting I believe) that it is an autosomal recessive trait, so mom and dad would be carriers. Have not been able to verify that. Also, considering there can be multiple reasons for retained testicles, I find it hard to believe.

I posted a similar question to the GSD Euro group recently and got zero feedback. So it will be intersting if anyone can post some facts/studies here.

--Mary

I believe that it must be a simple autosomal recessive (that is, carried by both parents). 

For example, I know of close linebreeding on a dog who had a single cryptorchid littermate (of 3 litters--2 of them repeats)--from a dam who produced one unilateral crytorchid in each litter--regardless the sire.

There have been no cryptorchids on 2-3 linebreeding with grandsons of the first male--despite the fact that their dam (a daughter of the first male) had one cryptorchid littermate. The 2-3 linebreeding is about to be done for a fourth litter.

Research, studies? Guess what I'm relating may be regarded as purely annecdotal--which is good enough for me.

It is a recessive gene and both parents must have it. Sometimes it is many generations back.
Prager (Hans)
http://www.alpinek9.com

http://en.wikipedia.org/wiki/Cryptorchidism

http://books.google.com/books?id=UtXQ5fI2cngC&pg=PA48&lpg=PA48&dq=causes+of+retained+testicle+in+dog&source=bl&ots=mjFS65TJiU&sig=mdjZUV_JU3VOfszCUiYpe7cahfI&hl=en&ei=RrXhSuifEo3j8Abkw5z8AQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CA8Q6AEwATgK#v=onepage&q=causes%20of%20retained%20testicle%20in%20dog&f=false

http://www.alvervets.co.uk/html/pdf/Factsheets/Dog/24_282895.pdf

http://www.ncbi.nlm.nih.gov/pubmed/18684574?ordinalpos=8&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

http://www.ncbi.nlm.nih.gov/pubmed/31014?ordinalpos=98&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum


--Mary