Believe it or not, science has been tampering with feline genetics for years, trying to genetically alter cats to produce a viable breeding strain that lacks the Fel d1 protein.
Clients that experienced an allergic reaction are said to be extremely allergic to cats and are believed to have had a reaction to an allergen other then FEL D1.
Actually, what causes the reaction is a glyco-protein known as Fel d1 that is found in cat saliva and urine, as well as in the sebaceous glands.
The theory has always been that Siberians produce a significantly lower level of the Fel d1 protein than most other cat breeds.
The source of cat allergies in humans is in a minuscule glycoprotein called Fel D1.
The operator d1= aoaai+aiaa2+a20a3+...
Chara sp., oogonium and D1.