This Is AuburnElectronic Theses and Dissertations

Comparison of the gene encoding the thyroid-stimulating hormone receptor between hyperthyroid and non-hyperthyroid domestic cats.




Haysom, Laura

Type of Degree

Master's Thesis


General Veterinary Medicine


The prevalence of feline hyperthyroidism (FH) is increasing, yet the etiology of FH remains to be elucidated. The purpose of this study was to compare exons 1 to 5 of the thyroid-stimulating hormone receptor (TSHR) gene and the predicted encoded amino acids between hyperthyroid and unaffected cats. Genomic DNA was isolated from whole blood of hyperthyroid and non-hyperthyroid cats. Exons 1 to 5 of the TSHR gene were amplified and sequenced. DNA and amino acid sequences were compared to identify differences between phenotypes. We identified 4 polymorphisms; 1 SNP in Exon 1 (Al-10-Val), 2 SNP in Exon 4 (silent mutations) and 1 SNP in Exon 5 (Al-139-Gly). In Exon 4, some cats had an intronic 30 base pair insertion and one hyperthyroid cat had a 2 base pair deletion upstream of the coding sequence. Finding a genetic basis for FH would have important implications for its treatment, screening and prevention.