Narcolepsy (canarc1 Doberman)During the Narcolepsy (canarc-1) suffer dogs cataplectic episodes, a sudden onset of temporary flaccid paralysis of individual muscle groups or the entire skeletal musculature. Triggers are exciting events or fright. Affected dogs also show particular Fatigue during the day.
This genetic variant of the disease occurs in Doberman from. It is inherited autosomal recessively.
– Fatigue during the day Cataplexy → sudden onset of transient flaccid paralysis of individual muscle groups (partial paralysis) or of the entire skeletal musculature (total paralysis) – partial paralysis: z.B. Weakness of the hind legs leading to sudden sitting down – total paralysis: falling down with subsequent immobility
– The first symptoms appear in the first 6 months of life At. – Triggers are excitatory events (feeding, playing). – The paralytic state lasts from a few seconds up to five minutes. – Touching or loudly addressing the dog terminates the seizure and is completely reversible. – The severity of the disease is indicated by the Frequency of cataplectic episodes Defined within a certain period of time.
Involved gene | DNA test
This mutation test detects a SINE insertion ( nt3Pos750Ins226 ) in the HCRTR2 gene.
→ The disease occurs only when both alleles of the gene are affected by the mutation (narc/narc). Dogs that have only one allele with the causative mutation (N/narc) are clinically healthy carriers. The dog has no predispositions for narcolepsy. Thus, cannot pass them on to offspring.
N/ narc = a carrier
narc / narc = Affected
100% of the variation is passed on to the offspring. The offspring are carriers or affected.
Recommendations for breeding
– Carrier animals can be mated with normal animals (N/ narc x N/N). Before progeny are used in breeding, testing should be done to determine whether they are normal or carriers. – Mating of two carrier animals (N/ narc x N/ nar c) should be avoided because there is a 25% chance that the offspring are affected. – Affected animals ( nar c/ nar c) should be excluded from breeding.
Lin, L., Faraco, J., Li, R., Kadotani, H., Rogers, W., Lin, X.Y., Qiu, X.H., de, Jong, P.J., Nishino, S., Mignot, E.: The sleep disorder canine narcolepsy is caused by a mutation in the hypocretin (orexin) receptor 2 gene Cell 98:365-376, 1999. Pubmed reference: 10458611 .
Hungs, M., Fan, J., Lin, L., Lin, X.Y., Maki, R.A., Mignot, E.: Identification and functional analysis of mutations in the hypocretin (orexin) genes of narcoleptic canines Genome Research 11:531-539, 2001. Pubmed reference: 11282968 . DOI: 10.1101/gr.161001 .