Approximately 10 million people in the U.S. are allergic to cats, according to the nonprofit Asthma and Allergy Foundation of America (related feature: "Allergies: A Modern Epidemic" in National Geographic magazine).
Cat allergens can trigger severe asthma attacks for 20 to 30 percent of asthma sufferers and exposure can lead to chronic asthma.
Contrary to popular belief, people are not allergic to a cat's fur or dander. The sneezing, wheezing, and itching are brought on by Fel d 1, a protein excreted in feline saliva and skin glands.
Even a hairless breed can trigger an allergic reaction. Catsnotorious self-groomerstransfer the allergy-inducing protein to their skin and fur while licking themselves.
According to Young, Allerca researchers used genetic sequencing to search for natural variations in the genetic code of the Fel d 1 protein.
They then selectively bred cats to express the protein at a lower molecular weight, reducing the likelihood of an allergic reaction.
Allerca's low-allergen felines, expected to arrive in homes next spring, carry a price tag that could send some pet lovers into shock. The firm currently charges $3,950 (U.S.) per cat, plus nearly $1,000 for processing and transportation.
The steep cost includes pet insurance, vaccines, a microchip identifier, spaying or neutering, nail caps, and a starter kit. Kittens will be delivered via private jet courier to pre-selected veterinary offices where owners can pick them up.
Because building up a breeding pool takes time, Young projects that Allerca will only have 400 to 500 cats available next year.
As a safety precaution, Young says the kittens will be tested for their Fel d 1 levels before they are delivered. Owners and their homes must also undergo FDA-approved allergy tests to create a baseline for any preexisting allergens.
Should an individual exceed the threshold level for tolerating the new cats' low levels of allergens, Allerca will strongly suggest the owner not claim the cat and will refund the purchase price.
A Denver, Colorado-based firm, Felix Pets, is trying to produce hypoallergenic cats using a different technique: developing a hypoallergenic cat via direct cellular modification.
In theory, while a developing kitten is still a single cell, its DNA can be modified to remove or suppress the gene that produces the allergen protein, Felix Pets' president David Avner explains.
The modified cell would then be implanted into a surrogate mother cat to finish developing into an allergen-free kitten.
Avner says gene modification has an advantage over selective breeding in that modification takes less time to produce a cat consistently free of the allergen protein.
"To breed out the allergen could take decades," he said.
Avner says he expects to have transgenic allergen-free cats ready for the market by 2008. While kittens will be "expensive" initially, Avner said, he hopes to eventually sell them for $800 to $1,000.
Felix Pets is a division of New York-based Transgenic Pets, which brought a lawsuit against Allerca over intellectual property issues in 2004. That suit was settled out of court for an undisclosed sum in 2005.
According to Young, Allerca had been pursuing genetic modification until last year, when researchers ran into challenges silencing the allergen-producing gene.
But it was during this research that Allerca developed genetic testing to focus on less potent versions of the Fel d 1 protein.
Little is known about the exact role the Fel d 1 protein plays in cats, so no one is sure what effect removing or suppressing the protein would have on an animal.
Duane Kraemer is a professor of veterinary physiology and pharmacology at Texas A&M University in College Station, and the owner of "CC," the world's first cloned cat (related news: "Cat Cloning Offered to Pet Owners").
"The only way to determine that would be to do some of the knockout experiments and see how the cats do," Kraemer said, referring to clinical trials in which a target protein is "knocked out" of an animal's genetic code.
UC Davis' Lyons, agrees: "If [we learn] anything from these experiments these companies are doing, we might learn a lot about the physiology of this particular protein."
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