Clopidogrel is a drug frequently used to prevent blood clot formation in cats with heart disease.  A portion of cats are resistant to this medication or have less than expected response to treatment.  A mutation in the P2RY1 gene is associated with reduced response to this medication and cats harboring this mutation may benefit from altered drug dosing, selection of a different anti-thrombotic drug, or combined anti-thrombotic therapies under the consultation of a veterinarian.

Testing Prices:

P2RY1 mutation = $60.00 per cat

Sample Type for Submission:

Acceptable samples include a cheek swab or 1-2 mL whole blood collected in an EDTA tube. If these sample types are unavailable, please reach out to us at cvm-cardiacgenetics@ncsu.edu for more information. Alternative sample types may result in an additional charge.

Explanation of Results:

Two copies of each gene are inherited, one from each parent. Possible results include:

Negative

Negative cats have two copies of the normal, unmutated gene. Clopidogrel at a dose of 18.75 mg PO SID will most likely elicit adequate platelet inhibition in cats that tested negative for the test. However, very importantly, the absence of the mutation in this cat does not mean that this cat does not have resistance to clopidogrel since additional mutations may be identified that may be tested for as well.

Positive Heterozygous

Cats who are Positive Heterozygous for the P2RY1 mutation have 1 copy of the mutated gene and 1 copy of a normal gene. Clopidogrel at a dose of 18.75 mg PO SID will likely not elicit the expected platelet inhibition in cats that are positive for the test. For further recommendations, please consult with your veterinarian or have your veterinarian reach out to consult Dr. Li and our NC State Comparative Platelet and Neutrophil Laboratory at rhli2@ncsu.edu.

Positive Homozygous

Cats who are Positive Homozygous for the HCM mutation have 2 copies of the mutated gene. Clopidogrel at a dose of 18.75 mg PO SID will very likely not elicit the expected platelet inhibition in cats that are positive for the test. For further recommendations, please consult with your veterinarian or have your veterinarian reach out to consult Dr. Li and our NC State Comparative Platelet and Neutrophil Laboratory at rhli2@ncsu.edu.