Obesity (Labrador Retriever)

 

Gene: POMC

Transmission: Autosomal dominant (variable penetration); multifactorial

For an autosomal dominant genetic disease, an animal must have at least one copy of the mutation in question to be at risk of developing the disease.  Animals with two copies of the mutation generally have more severe symptoms and an earlier onset of the disease than animals with just one copy of the mutation.  One or both of the parents of an animal with the mutation has one or two copies of the mutation.  Animals that have one or two copies of the mutation can pass the mutation on to future generations.

Mutation: Deletion, POMC gene; c.561_575 del. 14pb, p.(E188 fs), exon3-4

Medical system: Metabolic

Breeds: Flat-Coated Retriever, Labrador Retriever

Age of onset of symptoms: 4 months of age and older

Labrador Retrievers are known to be a dog breed susceptible to problems of obesity and are also noted to be highly motivated towards good rewards.  A deletion within the POMC gene in Labradors was associated with body weight, appetite and obesity.  POMC is a gene that codes for a number of peptide hormones including several involved in metabolism and regulation of food intake.  Interestingly, the deletion was found to have an increased frequency in Labradors that were assistant dogs compared to the general Labrador population.  Labradors suffering from obesity are prone to increased incidence of joint damage and inflammation as well as increased difficulties in breathing compared to non-obese dogs, but do not have increased rates of diabetes.

 

References:

OMIA link: [1258-9615]

Sypniewski M, Szydlowski M. (2023) A study of 41 canine orthologues of human genes involved in monogenic obesity reveals marker in the ADCY3 for body weight in Labrador Retrievers. Vet Sci 10(6):390.  [pubmed/37368776]

Wallis NJ, Sumanasekera NT, Raffan E. (2022) Obesity risk factors in British Labrador retrievers: Effect of sex, neuter status, age, chocolate coat colour and food motivation. Vet Rec :e3410. [pubmed/37747436]

Wallis N, Raffan E. (2020) The genetic basis of obesity and related metabolic diseases in humans and companion animals. Genes 11:1378. [pubmed/33233816]

Davison LJ, Holder A, Catchpole B, O’Callaghan CA. (2017) The Canine POMC Gene, Obesity in Labrador Retrievers and Susceptibility to Diabetes Mellitus.  J Vet Intern Med. 31(2):343-348. [pubmed/28176381]

Mankowska M, Nowacka-Woszuk J, Graczyk A, et al. (2017) Polymorphism and Methylation of the MC4R Gene in Obese and Non-Obese Dogs. Mol Biol rep 44(4)333-339. [pubmed/28755272]

Mankowska M, Krzeminska P, Graczyk M, Switonski M. (2017) Confirmation that a deletion in the POMC gene is associated with body weight of Labrador Retriever dogs.  Research in Veterinary Science 112:116-118. [pubmed/28235700]

Raffan E, Dennis RJ, O’Donovan CJ, et al. (2016) A deletion in the canine POMC gene is associated with weight and appetite in obesity-prone Labrador retriever dogs.  Cell Metabolism 23:893-900. [pubmed/27157046]

Raffan E, Smith SP, O’Rahilly S, Wardle J. (2015)  Development, factor structure and application of the Dog Obesity Risk and Appetite (DORA) questionnaire. PeerJ. 3:e1278. [pubmed/26468435]