Myoclonus Epilepsy of Lafora
Breeds
Relevance Rating: There is moderate evidence or research available in this breed
Relevance Rating: There is some evidence or research available for these breeds
Relevance Rating: The test is unknown, there is no evidence (i.e. research) available, or it has not been evaluated yet. These tests may or may not be meaningful for these breeds
General
Disease Name
Myoclonus Epilepsy of Lafora
OMIA
690
Gene Name
NHLRC1
Mutation
19 to 26 copies of a sequence of 12 nucleotides in NHLRC1
Mutation Notes
19 to 26 copies of a sequence of 12 nucleotides (12-mer; dodecamer) in the canine EPM2B gene (now called NHLRC1)
Test Type
Genetic Disease/Disorder
Details
Lafora disease is an inherited late onset progressive myoclonic (jerking) epilepsy. Signs include jerking of the head / rapid shuddering triggered by flashing lights, sudden sounds and movement, partial seizures (including high-pitched noises and abnormal behaviour if the dog is panicking), and progression slowly over time to ataxia, blindness and dementia. Seizure-type symptoms can also occur while the dog is asleep. Age of onset from 5 years. Some breeds/types, such as the Beagle are reported to have a more severe form of the disease and can be drug resistant.
Details 2
Lafora disease (LD) is an autosomal recessive late onset, progressive myoclonic epilepsy with a high prevalence in the miniature Wirehaired Dachshund. The disease is due to a mutation in the Epm2b gene which results in intracellular accumulation of abnormal glycogen (Lafora bodies)... A characteristic feature of the disease is spontaneous and reflex myoclonus; however clinical signs and disease progression are not well described... Average age of onset of clinical signs was 6.94 years (3.5-12). The most common initial presenting sign was reflex and spontaneous myoclonus (77.8%). Other presenting signs included hypnic myoclonus (51.9%) and generalized seizures (40.7%). Less common presenting signs include focal seizures, "jaw smacking", "fly catching", "panic attacks", impaired vision, aggression and urinary incontinence. All these clinical signs may appear, and then increase in frequency and intensity over time. The myoclonus in particular becomes more severe and more refractory to treatment. Signs that developed later in the disease include dementia (51.9%), blindness (48.1%), aggression to people (25.9%) and dogs (33.3%), deafness (29.6%) and fecal (29.6%) and urinary (37.0%) incontinence as a result of loss of house training (disinhibited type behavior). Further prospective study is needed to further characterize the canine disease and to allow more specific therapeutic strategies and to tailor therapy as the disease progresses. (From Swain et al, 2017)
Published
Bradbury, J. : Canine epilepsy gene mutation identified. Lancet Neurol 4:143, 2005. Pubmed reference: 15744941.
Published 2
Lohi, H., Young, E.J., Fitzmaurice, S.N., Rusbridge, C., Chan, E.M., Vervoort, M., Turnbull, J., Zhao, X.C., Ianzano, L., Paterson, A.D., Sutter, N.B., Ostrander, E.A., Andre, C., Shelton, G.D., Ackerley, C.A., Scherer, S.W., Minassian, B.A. : Expanded repeat in canine epilepsy. Science 307:81, 2005. Pubmed reference: 15637270. DOI: 10.1126/science.1102832.
Published 3
Hajek, I., Kettner, F., Simerdova, V., Rusbridge, C., Wang, P., Minassian, B.A., Palus, V. : NHLRC1 repeat expansion in two beagles with Lafora disease. J Small Anim Pract 57:650-652, 2016. Pubmed reference: 27747878. DOI: 10.1111/jsap.12593.
Published 4
Swain, L., Key, G., Tauro, A., Ahonen, S., Wang, P., Ackerley, C., Minassian, B.A., Rusbridge, C. : Lafora disease in miniature Wirehaired Dachshunds. PLoS One 12:e0182024, 2017. Pubmed reference: 28767715. DOI: 10.1371/journal.pone.0182024.
Body/System/Process
Neurologic
OMIA Url
Inheritance
AR
Breed Specific Info
Researched Breeds
Beagle, Miniature Wirehaired Dachshund