Identification of beta-1 adrenergic receptor polymorphisms in cats.

In human beings, genetic polymorphisms within the beta-1 adrenergic receptor (ADRB1) gene have been associated with variable pharmacologic responses to beta blocker therapy. Beta-blockers are commonly given to cats with heart disease, particularly hypertrophic cardiomyopathy, a common cause of feline heart disease. We hypothesized that polymorphisms are present in the feline ADRB1 gene, which could result in an altered pharmacologic response to beta-blocker therapy. We sequenced the feline ADRB1 gene in 42 cats of five breeds. We identified three polymorphisms within the ADRB1 gene. Two polymorphisms did not change the amino acid produced and are unlikely to be clinically significant. A third polymorphism identified was an AA/CC substitution at the 830-831 base pair sites. This alteration changed the amino acid produced from proline to glutamine at position 277 and computer modeling predicts an altered protein structure. Further study is warranted to determine if this polymorphism alters response to beta blocker therapy.