NHLRC1 repeat expansion in two beagles with Lafora disease

Area of Science:

• Genetics
• Neuroscience
• Veterinary Medicine

Background:

• Lafora disease is a fatal, inherited neurodegenerative disorder.
• It is characterized by the accumulation of abnormal glycogen deposits in the brain.
• Mutations in EPM2A or NHLRC1 genes cause Lafora disease in humans.

Observation:

• A specific mutation in the NHLRC1 gene is known in miniature wirehaired dachshunds.
• Lafora disease is frequently reported in beagles, but the genetic cause was previously undocumented in this breed.
• This case report investigated the genetic basis of Lafora disease in two affected beagles.

Findings:

• The causative defect in beagles is a massive expansion of a 12-nucleotide repeat sequence.
• This repeat sequence is unique to the canine NHLRC1 gene.
• The identified mutation is identical to the one found in miniature wirehaired dachshunds.

Implications:

• This discovery identifies the first known genetic variant of Lafora disease in beagles.
• It suggests a shared genetic etiology for Lafora disease across different dog breeds.
• Understanding this genetic defect is crucial for canine genetic diagnostics and potential therapeutic strategies.