tokens: IGR - N - 91 had an abnormally high molecular weight protein due to the duplication of wild - type exons 7 - 8 - 9 , thus affecting the DBD and OD ; and LAN - 1 , with a mutation at codon 182 ( Cys - - > stop ) concurred with an earlier report showing extremely low levels of mRNA and undetectable protein expression ( 9 ) .