tokens: The most common causative genes among probands were PMP22 ( duplication ) ( n=116 , 58.88 % ) , GJB1 ( n=23 , 11.67 % ) , MFN2 ( n=12 , 6.09 % ) , GDAP1 ( n=7 , 3.55 % ) , MPZ ( n=6 , 3.05 % ) , PMP22 ( point mutation ) ( n=6 , 3.05 % ) , NEFL ( n=3 , 1.52 % ) , SBF2 ( n=3 , 1.52 % ) , and SH3TC2 ( n=3 , 1.52 % ) .