Background

Several breeds of cats have interesting morphological traits that help define their breed.  Manx, Munchkins and Scottish Folds are three breeds that have autosomal dominant traits that are unique to their breed.  Many lines of each of these breeds experience no health issues, but some lines have conditions that can be associated with the breed defining trait.  In order to help identify clear and potential lines with more risk, the Lyons' laboratory would like to identify the genes that control these traits.  Once the gene and the causative mutations are identified, further research can help determine why some lines are very healthy while a few have some health concerns due to the trait.

Please see below under Join the Project! to see how to participate in the research.

Genetics

Taillessness, dwarfism, and ear fold are all autosomal dominant traits.  This means the trait is not associated with the gender of the cat (not sex-linked) and that only one copy of the mutation is required to see the expression of the trait.  As is true for many dominant traits in many species, having two copies of the mutation, homozygous, can often lead to health problems or the condition is not viable.  For the Manx, the homozygous is lethal in utero and no homozygous kittens are produced.  For Scottish Fold, joint abnormalities (osteochondrodystrophy) is associated with the homozygous cats.  For Munchkins, no peer-reviewed evidence has been documented on health issues in the homozygous, but many breeders tend not to produce homozygous cats as it is feared that this may lead to severe limb and skeletal abnormalities. 

For these breeds, most cats are bred to a cat that does not have the trait, such as tailled to no tail, Fold to Straight-eared, or short to long legged.  These types of breedings are PERFECT for genetic studies.  Thus, for the gene mapping studies, we just need to collect DNA samples from regular breedings for these three breeds.  Nothing special has to be done!

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Human & Mice Traits

Several forms of dwarfism are know in humans and mice have a tailless condition.  Fold is rather unique to cats, but the condition could help us understand bone development and growth and maybe even osteoarthritis.  An excellent site to use to research these conditions in humans is "Mendelian Inheritance in Man".  A search here will present all the known heritable conditions in humans and extensive background information and references for each type of trait.    Whether a condition is dominant in humans, as in cats, may be a good indication of which gene to examine, but all genes should be considered.

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Clinical Presentation (coming soon)

Manx

Munchkin

Scottish Fold

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Clinical Management (coming soon)

Manx

Munchkin

Scottish Fold

Gene Hunting

To find the genes for these cat traits, we need to collect DNA samples from cats with and without the trait.  Both types of cats are equally important.  A minimum of three generations is required, grand-parents, parents and offspring.  Thus, one family will consist of the 4 grand-parents, 2 parents, and the kittens.  This would be 10 samples if 4 kittens are produced.  Twelve families of this type would allow us to start the projects.  Thus, we need twelve Manx, Munchkin, and Scottish Fold families.  Once all the families are collected, we will start the gene hunting.  It may take some time to collect the families, but the more enthusiasm by the breeders, the fast the project will go.  Families can also include half-sib relationships but all parents and grand-parents will be needed.  If the same breeding has produced more kittens, these would be very important to the study.  The larger the sibships the better.

Join the Project!

Breeders first need to contact the Lyons' Den laboratory to express their interest.  The laboratory will send buccal swabs and instructions for the DNA collection.  Four (4) swabs will be collected per cat.  Kittens should be as old as possible but before they leave the breeder.  Pedigrees should be submitted with the swabs.  Most importantly, the trait-type for each cat must be identified.

Manx: Full tail, rumpy, stumpy, riser.....

Fold: Straight ear or folded ear

Munchkin: Short or long legged.

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Information for sending samples can also be found on this website at: DNA Sampling and Shipping Protocols

Cat References

Other useful links:

Veterinary Genetics Laboratory (VGL)

Center for Companion Animal Health (CCAH)

California National Primate Research Center (CNPRC)

Center for Equine Health (CEH)

Department of Population Health & Reproduction (VM:PHR)

Last update: November 30, 2004 This site is under continual development. Please visit again soon! Many of the current pages are the place holders for future information. Please provide suggestions to the webmaster: felinegenome@ucdavis.edu