A San Diego-based biotech firm has started selling hypoallergenic cats. Allerca's kittens have been selectively bred to reduce the amount of a protein called FEL D1, which causes adverse reactions in allergy sufferers.

As New Scientist reported back in 2004, the firm publicly announced plans to genetically engineer cat DNA to eliminate production of FEL D1. It seems the plans hit technical problems though, and the "product" Allerca is offering is just a cat that has been selectively bred in the traditional fashion, albeit backed up by gene testing and for a novel purpose.

The first kittens will be shipped 2007, costing a total of $3,950 for US residents. Allerca hopes they'll be the first in a series of what it calls "lifestyle pets".

Allerca says it has conducted scientific trails proving their cats don't cause the sneezing, eye-watering, skin and breathing problems experienced by allergic pet owners. A statement said: "Individuals with known feline allergies were fully exposed to the Allerca cats without demonstrating any allergic reactions."

Allergy experts have expressed doubts over whether the animals can be completely hypoallergenic, as FEL D1 isn't the only protein responsible for difficulties. Cat albumin can also get a reaction.

Norman Edelman, chief medical officer of the American Lung Association, told New Scientist: "This approach is scientifically valid, but that doesn't mean it's going to work." ®