<unk>  is considered an extremely rare disorder, though little epidemiological work has been done. Prevalence is generally higher in European-derived populations and lower among Asians. Epidemiological estimates have been provided for the German population. There, it was estimated that the prevalence of<unk>  is between 1:350,000 (0.00028%) and 1:180,000 (0.00056%). However, the German population of patients with<unk>  is not uniformly distributed across the country. Many individuals with<unk>  herald from the Ravensberg area in North-West Germany, where a founder effect seems to be responsible for most cases. The prevalence here is estimated at 1:6000 or 0.017%.
Paramyotonia congenita
Myotonia congenita
Periodic paralysis
Klumpke paralysis
Quadrigia
Paroxysmal kinesigenic choreoathetosis
Ataxic cerebral palsy
Cramp fasciculation syndrome