▁is ▁regarded ▁as ▁a ▁Finn ish ▁her itage ▁disease . ▁Un like ▁most ▁Finn ish ▁her itage ▁dise ases , ▁this ▁synd rome ▁has ▁been ▁reported ▁only ▁in ▁Finland . ▁The ▁disease ▁is ▁character ized ▁by ▁se iz ures ▁in ▁early ▁child hood ▁that ▁progress ively ▁get ▁worse ▁until ▁after ▁pub ert y . ▁Once ▁the ▁on set ▁of ▁se iz ures ▁occurs , ▁mental ▁de grad ation ▁is ▁seen . ▁This ▁continues ▁into ▁ad ul th ood , ▁even ▁after ▁se iz ure ▁frequency ▁has ▁decre ased . ▁The ▁cause ▁of ▁the ▁disease ▁is ▁a ▁miss ense ▁mut ation ▁on ▁chrom os ome ▁ 8 . ▁The ▁creation ▁of ▁a ▁new ▁protein ▁occurs , ▁and ▁the ▁li pid ▁content ▁of ▁the ▁brain ▁is ▁alter ed ▁because ▁of ▁it . ▁The ▁ratio ▁of ▁the ▁mut ation ▁carri ers ▁is ▁ 1 : 1 3 5 . ▁There ▁is ▁nothing ▁that ▁has ▁been ▁found ▁to ▁stop ▁the ▁pro gression ▁of ▁the ▁disease , ▁but ▁sympt om atic ▁approaches , ▁such ▁as ▁the ▁use ▁of ▁ben z odia ze p ines , ▁have ▁helped ▁control ▁se iz ures . ▁ ▁Character istics ▁ ▁Early ▁child hood ▁ ▁Northern ▁ep ile ps y ▁synd rome ▁causes ▁rec urrent ▁se iz ures ▁between ▁the ▁ages ▁of ▁five ▁to ▁ten . ▁These ▁se iz ures , ▁that ▁may ▁last ▁up ▁to ▁ 1 5 ▁minutes , ▁can ▁be ▁class ified ▁mostly ▁as ▁t onic - cl onic , ▁but ▁partial ▁se iz ures ▁could ▁also ▁occur . ▁The