Diabetes mellitus (DM) is a common endocrinopathy in dogs. Breed susceptibilities (eg, overrepresentation in Samoyeds, relative absence in boxers) suggest genetic factors. This report compared genes linked with DM susceptibility in humans with genes (some of which are breed specific) linked with susceptibility in dogs.
A deficiency of endogenous insulin causes DM in dogs to resemble type 1 diabetes (T1D) in humans; however, because exocrine pancreatic diseases of immune-mediated mechanisms are implicated, it may be similar to latent autoimmune diabetes for adults (LADA). In humans, T1D and LADA are linked to a region of chromosome 6 containing human leukocyte antigen (HLA) genes, with differences in amino acid sequences around the major histocompatibility complex (MHC) class II molecules. Increased DM risk in dogs was associated with MCH class II genes (dog leukocyte antigen), with similar haplotypes and genotypes seen in most susceptible breeds. A region containing a variable number of tandem repeats and several single nucleotide polymorphisms has been identified. Some alleles are associated with susceptibility or resistance to DM in a breed-specific manner; thus, an underlying genetic basis may vary between breeds. It is hoped that genome-wide association studies will shed light on the pathophysiology and genetic basis of DM, possibly guiding interventional genetic therapy.
Genetics of canine diabetes mellitus: Are the diabetes susceptibility genes identified in humans involved in breed susceptibility to diabetes mellitus in dogs? Catchpole B, Adams JP, Holder AL, et al. VET J 195:139-147, 2013.