Two types of NCL have so-far been found almost exclusively in Finland: Finnish variant late infantile NCL, vLINCL (CLN5), and the Northern epilepsy syndrome or Progressive epilepsy with mental retardation, EPMR (CLN8).
A missense mutation in CLN8 causes progressive epilepsy with mental retardation (EPMR) or Northern epilepsy, which has so far been reported only from Finland and is now classified as an NCL.