|Posted on April 21, 2010 at 3:49 AM|
Many people adopt Siberian kittens and cats because the breed is said to be hypoallergenic. However, not every Siberian cat *is*hypoallergenic. Therefore, how can you be sure that the kitten you adopt actually is hypoallergenic?
First, the bad news: you can't. Even though the (successful) genetic mutation that causes some Siberian cats to be hypoallergenic has been identified, currently there is no commercially available genetic test for this trait. Even kittens born to low allergen parents can be high allergen themselves.
Second, the good news: about 40% of all Siberian Forest Cats are hypoallergenic. Just by selecting the Siberian Forest Cat breed, you already have a 40% chance of adopting a hypoallergenic kitten!
Third, check out your breeder. Does she laboratory test her breeding cats for allergen levels? Will she share the actual laboratory reports with you, or are you expected to take them on faith?
Fifth: play by the numbers. By using a Punnet Square, we can calculate the statistical probabilty that any given kitten will or will not be hypoallergenic. First, we need to know that the trait is heterozygously inherited (in other words, at most a cat will have one positive mutation for low allergen status and one normal allele which gives the higher allergen results of typical felines), and that it is dominant. A dominant gene will be expressed if it is inherited, regardless if the other allele inherited gives directions for a different trait.
So, let's take a look at what we'd get by creating this punnet square chart. We'll assign the hypoallergenic Fel d-1 allele the letter F (capital F since the mutation is dominant), and we'll assign the normal, but recessive, Fel d-1 gene the letter f (a lower case f since it is recessive). From this Punnet Square, we learn that when we mate two low allergen Siberian adults together, we have a 75% probability that a kitten will be low allergen! Great odds!
Even if only one parent is hypoallergenic, we discover that a kitten's chances of being born low allergen are still great = 50%!
For the visual learners amongst us, here are the Punnett Squares to demonstrate this concept visually: