Polymorphisms in the serotonin transporter gene and circulating concentrations of neurotransmitters in Cavalier King Charles Spaniels with myxomatous mitral valve disease

Abstract

Background: The neurotransmitter serotonin (5-HT) affects valvular degeneration and dogs with myxomatous mitral valve disease (MMVD) exhibit alterations in 5-HT signaling. In Maltese dogs, 3 single nucleotide polymorphisms (SNPs) in the 5-HT transporter (SERT) gene are suggested to associate with MMVD. Hypothesis/Objectives: Determine the association of SERT polymorphisms on MMVD severity and serum 5-HT concentration in Cavalier King Charles Spaniels (CKCS). Additionally, investigate the association between selected clinical and hematologic variables and serum 5-HT and assess the correlation between HPLC and ELISA measurements of serum 5-HT. Animals: Seventy-one CKCS (42 females and 29 males; 7.8 [4.7;9.9] years (median [Q1;Q3])) in different MMVD stages. Methods: This prospective study used TaqMan genotyping assays to assess SERT gene polymorphisms. Neurotransmitter concentrations were assessed by HPLC and ELISA. Results: TaqMan analyses identified none of the selected SERT polymorphisms in any of the CKCS examined. Serum 5-HT was associated with platelet count (P