Confirmation that a deletion in the POMC gene is associated with body weight of Labrador Retriever dogs

A 14-bp deletion present in the proopiomelanocortin (POMC) gene of Labrador and Flat Coat Retrievers (FCR), but absent in POMC of other breeds, disrupts the β-MSH and β-endorphin coding sequences. This deletion was recently reported as strongly associated with increased body weight and obesity. We searched for this mutation in a cohort of 272 dogs, representing four breeds with a known predisposition to obesity (Labrador and Golden Retrievers, Beagle, and Cocker Spaniel) and, as expected, we found it only in Labradors. Further, we confirmed the association between the deletion variant and body weight of Labradors but not with a 5-point body condition score (BCS). We suspect that the deletion variant in our cohort may act as a recessive allele, unlike the previous study, which suggested its additive effect.