Missense variants in MC4R gene are associated with obesity in cats

Obesity stands out as the most common multifactorial nutritional problem affecting domestic cats. According to studies, the prevalence of overweight or obese cats varies between 11.5% and 63%. Various factors such as breed, age, gender, reproductive status, owner-pet relationship, diet type, and environmental factors have been identified as potential risk factors for the development of obesity in cats. Among the genes involved in regulating energy balance, one of the prominent genes is melanocortin-4 receptor gene (MC4R). A specific missense variant in the feline MC4R gene (c.92 C > T) has been associated with overweight in diabetic domestic shorthaired cats. In this study, it was aimed to determine the polymorphisms in MC4R gene in random bred cats and cats belonging to a registered breed in Turkey and to investigate their relationship with obesity. Blood samples from 30 obese and 20 non-obese cats were collected into sterile vacuum EDTA tubes. Exon 1 of the MC4R was amplified and sequenced. As a result of DNA sequence analysis, we identified a total of six SNPs in the feline MC4R gene, four of which were found for the first time in this study. As a result of comparing allele frequencies in obese and non-obese cats, a significant relationship was found between SNP rs783632116 and obesity. The results of regression analyses evaluating the effects of SNP genotypes, sex and infertility status on feline Body Mass Index (fBMI) indicated that non-synonymous SNPs rs783632116, ss11356259660 and ss11356259661 were significantly associated with fBMI.