How this cat connects, or does not connect, to an identified dominant blue eye variant. Generated from the register at build time.
What the proposed field says, and why it reads that way. A carrier with no result of its own and more than one identified variant above it. One test resolves it. The scheme is set out in full in the proposal. No registry issues this field today: it is computed from this cat's record at each build, so it changes by itself the day a laboratory result is entered, and nothing here has to be reissued.
Read this as parentage and nothing more. Each step is a parent recorded in the register from a pedigree or a breeder document. It shows how this cat descends from the founder of its line. It does not show which variant the cat carries, and it is not a substitute for a test.
This cat stands below more than one founder. The line named above is the one a source gives it. These are the others, reached by unbroken parent links from the register.
Two determinants stand above this cat and no test has been run on it. Which of them it carries, whether it carries more than one, or whether it carries none, is not established by any descent. Only a genotype settles it.
The grade above and this trace are not in conflict. The grade describes what is known about the variant, and no source asserts one for this cat. The trace is parentage, assembled by this survey from the documents behind each step. A cat can have a fully documented descent and still have nothing said about which variant, if any, came down it.
| Generation | Cats held | Carrying a variant |
|---|---|---|
| 1 | 2 of 2 possible | none |
| 2 | 4 of 4 possible | none |
| 3 | 6 of 8 possible | none |
| 4 | 2 of 16 possible | none |
| Variant | Carried by, in this cat's ancestry |
|---|---|
| DBE-ALT | Nikita'l Seymour |
| DBE-CEL | Roxi |
This is the situation the survey exists to flag. Two different dominant blue eye variants sit above this cat. A cat descending from both can inherit both variants at once, and the compound state, one copy of two different variants, is where the published deafness is reported. Abitbol and colleagues, Animals 2024, describe two white deaf kittens compound heterozygous for DBE-CEL and DBE-ALT.
Whether this cat carries either, or both, or neither, is not shown here and cannot be. Descent puts a variant within reach; it does not put it in the animal. Only a test on this cat settles it, and where two variants are in reach the test has to cover both: a clear result for one says nothing about the other.
This cat has never been tested. Everything above rests on documents and descent. Descent from a line is not a genotype. A cat can stand in a line and carry nothing, and a blue eye can be caused by white, by colourpoint or by low iris pigment with no PAX3 variant involved.
This is not a health certificate. It says nothing about hearing, and nothing about whether this cat should be bred from. Deafness in this trait is associated with carrying two different variants at once, which no pedigree can show and only a test can.
This directory is built from what people send it. For this cat it does not hold:
Sending a pedigree, a photograph or a test result. A pedigree has to be one a registry or club issued, because that is the only document that settles a parent; a breeder chart is welcome but is recorded at a lower grade and cannot draw a descent. The contact page says what to send and how. A correction is as welcome as an addition: where this page is wrong about your cat, the record is changed and the source you supply is named on it.