MDR1 Gene Defect / Multidrug resistance 1 syndrome

Test can detect deadly genetic mutation in cats

A new test developed by Washington State University researchers can detect a rare genetic mutation in cats that can cause potentially deadly reactions to some common medications, including those used to control parasites and in routine surgical procedures, like spays and neuters.

The only way to tell if a cat has the mutation, which is found in about 4% of all cats, is through a genetic test, which is available to pet owners and vets at Laboklin.

The test was developed by Dr Katrina Mealey, who, along with her team set up 'Program in Individualized Medicine (PrIMe)' at WSU's College of Veterinary Medicine have been working to develop the test and identify drugs that may be toxic to affected cats since 2014 when they discovered the mutation, which occurs in the MDR1 (multidrug resistance 1) gene, also known as the ABCB1 gene. The gene plays an important role in limiting drug distribution to the brain and in enhancing the excretion of many drugs.

Katrina Mealey is also responsible for the initial discovery of the MDR1 mutation in dogs in 2001 and for leading the development at WSU of the first commercial tests for canines.

'The mutation is probably about as common in cats as it is dogs, except that in dogs we know it is more breed specific,' Mealey said. 'So, if you have a collie, we know the animal has a 75% chance of having the mutation. In cats, though, it seems to be widely distributed and not breed specific.'