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Karlin
19th November 2009, 05:01 PM
In the Veterinary Journal. Link:

http://dx.doi.org/10.1016/j.tvjl.2009.10.022


Heritability of syringomyelia in Cavalier King Charles spaniels

Tom Lewisa , Clare Rusbridgeb, Penny Knowlerb, Sarah Blotta and John A. Woolliamsc

aAnimal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK

bStone Lion Veterinary Hospital, Wimbledon, London SW19 5AW, UK

cRoslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian EH25 9PS, UK


Accepted 20 October 2009. Available online 13 November 2009.
Abstract

Mixed model analysis of 384 Cavalier King Charles spaniels (CKCS), with a magnetic resonance imaging diagnosis for the presence or absence of a syrinx, in conjunction with the Kennel Club pedigree records of all dogs registered from the mid 1980s to September 2007, revealed a moderately high estimate of heritability of syringomyelia (h2 = 0.37 0.15 standard error) when analysed as a binary trait. Inspection of cases where the disease segregated within families pointed to genes at more than one locus influencing syringomyelia. The availability of estimated breeding values for Kennel Club registered CKCS is a significant step in being able to select against syringomyelia, particularly given the difficulty of ascertaining the disease phenotype.

Oreo
19th November 2009, 05:26 PM
"when analysed as a binary trait. Inspection of cases where the disease segregated within families pointed to genes at more than one locus influencing syringomyelia."

Is this confirmation, then, that CM/SM is polygenic?

Karlin
19th November 2009, 05:28 PM
They will not have that answer until the genome scan is finished and successful.

RodRussell
19th November 2009, 05:35 PM
I could use a layman's translation of that abstract.

Karlin
19th November 2009, 05:38 PM
Clare or Penny will likely be happy to give one. :) I'll email to see.

Oreo
19th November 2009, 06:20 PM
I know I'll be eagerly waiting for Rod to publish a layman's translation of the abstract on Cavalier Health Org.:cffee:

For others who read these abstracts and get a bit lost, I thought I could tip them off to this site I found which has been set up by the canine genetics group.

The glossary section of it is here.

http://dogdimension.org/dokuwiki/doku.php?id=shared:ch09

. . . .and the genetics primer is here.

http://dogdimension.org/dokuwiki/doku.php?id=shared:ch02

I have honestly never read anything on line which relates so much in a straight forward manner, so I'm quite excited about it.

There is also a valuable collection of articles to the left of the glossary.

Karlin
19th November 2009, 06:27 PM
Thanks! That is really useful information. :)

Bet
19th November 2009, 07:35 PM
I wonder if the 384 Cavaliers mentioned in this Analysis, had Smaller Heads, this is around the time that Cavaliers Heads were getting Smaller with Deeper Stops.

Does this mean that it will be quite a while before the the SM Genes are found ,since they are mentioned as being at more than one Locus influencing SM.

Bet
19th November 2009, 07:53 PM
I wondered what a Binary Trait meant, so went onto the Internet to find out, in case there are others like me wondering about this,

Complex Binary Traits have a Dichotomous Phenotypic Expression. ...but don't show a simple Mendalian Segration Ratio

These Traits are considered to be jointly controlled by the actions of Several Genes and a Random Environmental Effect.

EddyAnne
19th November 2009, 08:51 PM
These Traits are considered to be jointly controlled by the actions of Several Genes and a Random Environmental Effect.

Bet I heard Dr. Guy Rouleau in the video he mentioned GeneS, and I even heard him mention that DNA Researchers found high LOD scores on Chromosomes 9 and 15. Yes I think that CM/SM involves Complex Genetics.

Bet you mentioned Random Environmental Effect. In the Abstact note Tom Lewis and Sarah Blott plus the EBV Program then note the following about Environmental Effects, and the following from this link address.
http://www.thecavalierclub.co.uk/health/ebv/call_for_data.html

"EBVs are an objective numerical assessment of the genetic status of an individual dog, with environmental effects removed."
.