ATXN2 and nervous system disorder: To exclude possible genetic overlap with other nervous system diseases such as SCAs and amyotrophic lateral sclerosis (9, 18) and to further exclude dynamic mutations, large fragment deletions or duplication mutations, a panel of SCA-related gene (ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7, ATXN8, ATXN10, PPP2R2B, TBP, and ATN1) testing was also conducted, using gene microarray analysis.