In other species: cattle

Possibly relevant human trait(s) and/or gene(s) (MIM number): 254780

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal Recessive

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2005

Mapping: Lohi et a. (2005) undertook a "genome-wide scan genotyping 241 canine specific microsatellite markers (http://research.marshfieldclinic.org/genetics/) spanning the entire canine genome in the 14 affected dogs and four unaffected relatives". In dping so, they mapped the locus for this disorder to a region of CFA35 orthologous with the genes which are mutated in human Lafora's disease (EPM2A and EPM2B).

Molecular basis: In the first example of an inherited disorder in domesticated animals being shown to be due to an expanded repeat, and following a comparative positional cloning strategy (see Mapping section above), Lohi et al. (2005) reported affected Miniature Wirehaired Dachshunds as having 19 to 26 copies of a sequence of 12 nucleotides (12-mer; dodecamer) in the canine EPM2B gene (now called NHLRC1). This repeat occurs only twice or three times in normal dogs of a wide range of breeds. Hajek et al. (2016) reported the same expansion variant in two affected Beagles.

Breeds: Beagle, Miniature Wirehaired Dachshund.

Associated gene: