Epilepsy, myoclonus of Lafora

 

Gene: NHLRC1

Transmission: Autosomal recessive

For an autosomal recessive genetic disease an animal must have two copies of the mutation in question to be at risk of developing the disease. Both parents of an affected animal must be carriers of at least one copy of the mutation. Animals that have only one copy of the mutation are not at risk of developing the disease but are carrier animals that can pass the mutation on to future generations.

Mutation: Insertion, NHLRC1 gene; insertion, repetitions of 12 nt.

Medical system: Neurologic

Breed: Beagle, Chihuahua, Dachshund Miniature Wirehair, Newfoundland, Pembroke Welsh Corgi

Age of onset of symptoms: Around the age of 5 to 7 years

Lafora epilepsy is a late onset, chronic neurological disease characterized by recurrent epileptiform seizures and uncontrolled rapid muscular contractions (myoclonus).  Affected dogs start to show clinical signs around the age of 5 to 7 years.  As the disease progresses other signs can appear such as depression, blindness, drowsiness, ataxia and dementia.  Myoclonic seizures can be local, with movements of the head for example, or generalized with tremors of all the muscles of the body or can involve violent contractions of the head and neck.  External stimuli such as light effects can trigger these crises, but they can also appear without any apparent stimulus.  The disease is progressive and does not respond well to treatment.

 

References:
OMIA link: [0690-9615]

Cerda-Gonzalez S, Packer RA, Garosi L, et al. (2021) International veterinary canine dyskinesia task force ECVN consensus statement: Terminology and classification. J Vet Intern Med 35:1218-1230 [pubmed/33769611]

Flegel T, Kornberg M, Mühlhause F, et al. (2021) A retrospective case series of clinical signs in 28 Beagles with Lafora disease. J Vet Intern Med 35(5):2359-2365.  [pubmed/34486182]

Mari L, Comero G, Mueller E, et al. (2021) NHLRC1 homozygous dodecamer expansion in a Newfoundland dog with Lafora disease. J Small Anim Pract 62:1030-1032.  [pubmed/34263924]

Barrientos L, Maiolini A, Häni A, Jagannathan V, Leeb T. (2019) NHLRC1 dodecamer repeat expansion demonstrated by whole genome sequencing in a Chihuahua with Lafora disease. Anim Genet 50(1):118-119.  [pubmed/30525203]

Kehl A, Cizinauskas S, Langbein-Detsch I, Mueller E. (2019) NHLRC1 dodecamer expansion in a Welsh Corgi (Pembroke) with Lafora disease. Anim Genet. 50(4):413-414. [pubmed/31172540]

Ahonen S, Seath I, Rusbridge C et al. (2018) Nationwide genetic testing towards eliminating Lafora disease from Miniature Wirehaired Dachshunds in the United Kingdom. Canine Genet Epidemiol. 5:2. [pubmed/29610669]

Swain L, Key G, Tauro A, et al. (2017) Lafora disease in miniature Wirehaired Dachshunds.  PLoS One 12(8):e0182024. [medline/28767715]

Hajek I, Kettner F, Simerdova V, et al. (2016) NHLRC1 repeat expansion in two beagles with Lafora disease. J Small Anim Pract. 57(11):650-652. [pubmed/27747878]

Uriarte A, Maestro Saiz I. (2016) Canine versus human epilepsy: Are we up to date? J Small Anim Pract. 57(3):115-21. [pubmed/26931499]

Sainsbury R (2014) DNA screening for Lafora’s disease in miniature wire-haired dachshunds. Vet Rec. 175(22):568. [pubmed/25480901]

Lohi H, Young EJ, Fitzmaurice SN, Rusbridge C, et al. (2005) Expanded repeat in canine epilepsy. Science 307:81. [pubmed/15637270]