Molecular screening for the mutation associated with canine degenerative myelopathy (SOD1:c.118G > A) in German Shepherd dogs in Brazil

Abstract

Canine Degenerative Myelopathy is a late onset recessive autosomal disease characterized by a progressive ascending degeneration of the spinal cord. Two causal mutations are associated with this disease: a transition (c.118G>A) in exon 2 of the SOD1 that was described in several breeds and a transversion (c.52A>T) in exon 1 of the same gene described in Bernese Mountain dogs. The aim of this study was to understand the impact of the SOD1:c.118G > A mutation by genotyping a population of German Shepherd dogs in Brazil. A PCR-RFLP approach was used to genotype 97 healthy individuals belonging from the Northeast (Bahia and Pernambuco states) and South (Santa Catarina state) regions of Brazil. A total of 95 individuals were successfully genotyped resulting in an observed genotype frequency (with 95% confidence interval) of: 0.758 (0.672–0.844), 0.242 (0.156–0.328) and 0.000 (0.000–0.000) for “GG”, “AG” and “AA” genotypes, respectively. To our knowledge, this is the first attempt to describe the presence of the “A” allele associated with CDM (SOD1:c.118G > A) in German Shepherd dogs in Brazil and, as such, these results contribute toward important epidemiological data in this country and to the knowledge of the distribution of the aforementioned mutation worldwide.