Association of obesity and MC4R gene in cats

Obesity stands out as the most common multifactorial nutritional problem affecting domestic cats. Studies conducted in many countries have found that 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, owners' perceptions of their cat's body condition, diet type, feeding frequency, 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, prominent genes are proopiomelanocortin (POMC) and melanocortin-4 receptor (MC4R). While mutations in POMC are considered as causes of obesity in humans and dogs, their role in feline obesity and diabetes has not yet been explored. Conversely, a specific genetic variant in the feline MC4R gene (c.92C>T) has been associated with both overweight and diabetes in domestic shorthair cats. The aim of this study was to determine in MC4R polymorphisms in random bred and pedigree cats 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 regression analyses evaluating the effects of SNP genotypes, sex and infertility status on feline Body Mass Index (fBMI) indicated that SNPs rs783632116, ss11356259660 and ss11356259661 were significantly associated with fBMI.