, ▁and ▁the ▁most ▁common ▁miss ense ▁mut ation ▁occurs ▁at ▁cod on ▁ 2 4 , ▁where ▁a ▁g ly c ine ▁takes ▁the ▁place ▁of ▁an ▁arg in ine . ▁This ▁primary ▁mut ation ▁can ▁also ▁be ▁pa ired ▁with ▁a ▁miss ense ▁at ▁cod on ▁ 2 3 7 , ▁where ▁an ▁arg in ine ▁takes ▁the ▁place ▁of ▁a ▁g ly c ine . ▁When ▁the ▁two ▁mut ations ▁interact , ▁a ▁length ened ▁pro gression ▁of ▁the ▁disease ▁is ▁observed . ▁The ▁primary ▁mut ation ▁( Arg 2 4 G ly ) ▁creates ▁the ▁protein ▁CL N 8 . ▁ 1 ▁in ▁every ▁ 1 3 5 ▁people ▁of ▁Finn ish ▁descent ▁were ▁reported ▁to ▁be ▁a ▁car rier ▁of ▁the ▁mut ation . ▁The ▁difference ▁between ▁ 1 - CL N 8 ▁and ▁ 2 - CL N 8 ▁is ▁the ▁amount ▁of ▁mut ations ▁and ▁the ▁mut ation ' s ▁location ▁in ▁the ▁chrom os ome . ▁ ▁Path oph ys i ology ▁ ▁An ▁accum ulation ▁of ▁transm emb rane ▁protein ▁is ▁seen ▁in ▁the ▁brain ▁t issue ▁of ▁Northern ▁ep ile ps y ▁patients . ▁This ▁protein ▁is ▁a ▁ 2 8 6 ▁am ino ▁acid ▁transm emb rane ▁protein ▁that ▁has ▁not ▁been ▁identified ▁before , ▁meaning ▁that ▁it ▁is ▁unique ▁to ▁Northern ▁ep ile ps y ▁synd rome . ▁CL N 8 ▁has ▁been ▁linked ▁to ▁the ▁accum ulation ▁of ▁sub unit ▁c ▁of ▁mit och ond rial ▁ATP ▁synth ase ▁and