Research Samples NEEDED!
Molecular mapping and characterization of the genetic modifier associated with Collie Eye Anomaly (CEA) – a request
The aim of our research is to use genetic mapping (mainly GWAS) with high-density SNP-chip technology to identify a coloboma candidate genomic region. Such study pinpoints higher frequency of certain SNPs in cases vs. controls, associating these variations with the disease. GWAS can be implemented on a wide population of dogs with reasonable computation time, and regardless of the family information of the samples.
Our plan for the investigation of CEA gene modifiers in Collie is based on gathering a number of informative Collie samples with a well characterized phenotype and have them genetically tested for the primary genetic variant. These criteria are essential for building a reliable dataset. Thus, in a given population of Collie samples, we can classify dogs as belonging to one of these three categories: population of Collie samples, we can classify dogs as belonging to one of these three categories:
“A”- homozygous for the tested variant but only having choroidal hypoplasia;
“B”- same, but being affected by choroidal hypoplasia AND coloboma;
“C”- normal eyes and genetically normal for the tested genetic variant. For the sake of our research, only dogs from populations A and B are relevant. Out of all the genotyped collies in our dataset, 25 are population A and 20 are population B.
GWAS Population A vs Population B has been carried out using several different statistical models. Two candidate loci have been found associated with the severe condition, but currently, the association found is not very strong.
We think that we need to increase considerably the number of Collies participating to this study. This would allow us to increase our statistical power and also to suppress any confounding factor associated with specific populations of collie, close relatedness and so on.
We have determined that at least 20 new contributors per type would be ideal. However, we do think that an additional 10 dogs for each population could already improve our analysis results. Reaching a sufficient number of dogs for significance is our absolute priority. We count on the contribution of the breeders/owners for such advancement.
Once the mapping is complete and the statistics solid, Whole Genome Sequencing (WGS) will be then used to find the genetic modifier associated with CEA in Collies, which will be validated, and help in the development of a specific DNA test for diagnosis.
We wish to thank the Collie Health Foundation, especially Ms. Robette Johns, for their continuous help, interest and support, and the breeders for their precious contribution. We are looking forward the next developments of our research.
But please, keep those samples coming. While we state that 20 for each category would be needed, and we would settle for 10 for each initially, image the power if we could get 50 for each category! That would make the project progress much more rapidly. Your help is greatly appreciated.
University of PA Eye Submission Form