Investigating the genetic basis of a Canine Motor-Sensory Neuropathy by HD Canine 170000 SNPs Array

The aims of the present research is to investigate the genetic basis of a canine motor-sensory neuropathy clinically very similar to human Charcot-Marie-Tooth (CMT) diseases; 40 clinical subtypes are described in literature, all these pathologies are reported to be inherited. Recently some cases of degenerative neuropathy in Rhodesian Ridgeback (RR) dogs have been clinically studied, RR can be considered a valuable animal model for CMT considering the literature dealing with hereditary developmental defects of Peripheral Nervous System in RR. 2 affected dogs showing fasciculations and tremors, atrophy, limb muscles degeneration plus demyelination and myelin outfolding were considered the starting point of the family tree investigation. Clinical and histological tests of the affected dogs resulted in a description reporting clinical and histological characters very similar to human CMT (subtypes: CMT4B-1, CMT4B-2 and CMT4H; inheritance: autosomal recessive). MTMR2, MTMR13 and FGD4 respectively are considered to be the causative genes for these form of the disease. Biological samples of three healthy dogs and three affected ones, all related by pedigree, were collected. Parentage was verified comparing the subjects genetic profiles . MTMR2, MTMR13 and FGD4 human genes were identified on dog genome nucleotide sequence assembly and homology and conservation were evaluated. Genome-wide Association (GWA) approach by 170.000 high-density SNPs DNA microarray (Illumina) to map potential candidate genes for CMT disease were used. Using Homozigosity Mapping Seventeen candidate regions were described. The preliminary results underline the efficacy of the applied protocol, an increase of the number of affected dogs samples could be very useful.