Hello Labrador Enthusiasts!
Research plans for studying and defining TVD in Labrador Retrievers is about to be
funded...BY US, the Labrador community at large. Please post and share the following
information with all your Clubs and groups. Collectively, we should be able to fund this
research quickly. The National Labrador Retriever Club has made a goal of funding this
research, WITH the help of ALL the Clubs in and out of our country. We can join together,
as a unified group, and make this a reality.
Please, take it upon YOURSELF to start a fundraiser within your group/club/family and help
us with this project. The below information is the latest email from Penn Vet, where the research
will take place. I responded to Meg that we WILL DO this funding and she is working on a
budget, which I will post as soon as it arrives. Thank you for your participation. Now, let's do it!
-------- Original Message -------- Subject: TVD research
Date: Wed, 05 Sep 2007 11:40:24 -0400
From: Meg Sleeper <[email protected]>
I am sending this to you because you have contacted me previously with
an interest in supporting TVD research here at Penn Vet. I am including
a brief summary as an attachment, which also includes the estimated cost
of finding the mutation and developing a mutation based test for
breeding animals. We can proceed on several levels. Currently we are
collecting data and blood for DNA production from affected dogs. We
certainly plan to continue this process so that if/when money is
available, we can proceed with the DNA based testing. If there is enough
interest in the Lab breed organizations, we can perform further testing
as money is available. Please let me know your thoughts, and we can
develop a formal budget if you believe there is enough interest.
Tricuspid valve dysplasia (TVD) in dogs is similar to Ebstein’s anomaly in humans.
Both disorders involve congenital malformations of the tricuspid valve which result
in variable degrees of tricuspid valve regurgitation (TR). Dogs with the most severe
TR or tricuspid stenosis will typically develop right-sided congestive heart failure
within the first few years of life. The pathogenesis of tricuspid valve malformation
is largely unknown. Many dogs are only mild to moderately affected, and are not
identified until after they have become breeding animals. Labrador Retrievers, in
particular, seem to be predisposed to TVD. A previous study evaluated several kindreds
of Labrador retrievers, and determined, through clinical cardiology examinations,
pedigree analysis, and genetic analysis, that TVD is inherited as an autosomal dominant
trait with incomplete penetrance. Genetic analysis of dogs in the same study mapped a
susceptibility locus to canine chromosome 9 (CFA9). It is crucial to continue to examine
Labrador retriever kindreds through clinical cardiology examinations, pedigree analysis,
and genetic analysis for the future isolation of a gene or genes responsible for TVD.
Once isolated, genetic testing procedures can be developed, that will allow earlier
identification of dogs at risk for developing clinical signs, and at risk of passing
the disease to their offspring. A reliable test for identifying affected dogs not only
in Labrador Retrievers but in additional dog breeds, will allow breeders to markedly
decrease the prevalence of this often devastating congenital heart defect.
In order to further the research to find the TVD causing mutation we need:
1) Information and samples of either individual affected dogs or preferably as many
dogs as possible (affected and unaffecteds) from families with affected members. We
would ask for pedigree information, the clinical history and diagnosis and blood samples
(5 to 10 ml of EDTA blood) for DNA isolation.
2) Funds. The estimated cost for DNA isolation, initial sample analysis, and salary
support for one year would be approximately $50,000.