Hypoallergenic Siberian Cats?
Research has shown that all cats produce some Fel d1, but some cats produce considerably less than others. The Siberian Cat breed is thought to produce some of the lowest levels of Fel d1. There is strong anecdotal evidence from Siberian breeders and owners to support this theory, but scientific data is currently limited. The UC Davis University of California has now begun researching the hypoallergenic nature of Siberian cats and cats can be tested for the level of Fel d1 in their saliva.
The Siberian Research Inc has found a strong correlation between allergen levels in cat saliva and allergic reaction experienced by cat allergy sufferers. They have found that this trait for lower Fel d1 levels found in Siberian cats is genetic and is thus passed on to offspring.
You must remember that "hypoallergenic" means having a decreased tendency to provoke an allergic reaction, as opposed to the term "non-allergenic" which means having no tendency to provoke an allergic reaction. Therefore, some individuals allergic to Fel d1 will still react to the Siberian breed. Whether you react will depend on the severity of your allergy and the level of Fel d1 produced by the particular Siberian cat. It may also depend on the time of year and the amount of other allergens you are coming in contact with. The histamine response that your body produces when it attempts to counter an invading protein, has a cumulative effect in your body. So if it is hayfever season and you are affected your histamine levels will be up, then if your carpet is dusty that adds to the trouble, then if you eat high histamine food (yeast, aged cheese, processed meats etc) or drink alcohol) these add up too. Eventually you reach your tipping point where your body can't break down the histamine quick enough and your allergies start playing up. It is therefore important to use techniques to reduce your allergies even if you adopt a low allergen cat.

The Basics of Cat Allergies
A number of different allergens have been identified in cats, but can also be found in other mammals such as dogs, hamsters, and horses. The Fel d1 protein is created in the saliva, skin and anal glands of the cat. It is spread onto the cat's fur during grooming and once dry, it easily becomes airborne. It is not therefore the cat's fur that you may be allergic to and hence long haired or short-haired and even hairless cats can all cause reactions in allergic individuals.The Fel d1 production is regulated by the cat's hormones. It used to be thought that females produced lower levels of Fel d1 than males however recent research has dispelled this myth and it has been showed that both male and female Siberians can produce very low levels of the allergen. The level of Fel d1 does however increase as the cat matures and hormones increase and thus spaying/neutering will reduce the allergen levels produced by the cat. The increase of Fel d1 with age may explain why some people adopt a kitten only to find that they are allergic when the kitten grows up! That said, when living with a cat the repeated exposure to cat allergens may also reduce an individual's reaction to the cat. It is thought that high levels of exposure to the allergen may induce the production of "regulatory T cells" in the body.
If you suffer from allergies to other animals as well as cats, chances are you will still have an allergic reaction to a cat that has a low level of Fel d1 as it is likely one of the other proteins that you are reacting to. The Siberian Research Inc, a not-for-profit corporation, believes that if you are allergic to cats and not any other animals you are most likely only allergic to the Fel d1. They believe that Fel d1 accounts for around 60% of allergic reactions to cats.