Just found a direct answer to your question in a good reference on Russian cat breeds: http://messybeast.com/russian-breeds.htm
"It is claimed that Siberians [they're including Neva Masquerades if you read above in the same article] are hypoallergenic due to producing less of the Fel d1...
Just found your July post; hope this is still timely and you might find it useful. For the past six months, I've been trying to educate myself about Siberians and Neva Masquerades after adopting a beautiful young "medium hair tabby" from a shelter, then learning he's actually a Neva Masquerade...
