The original values are displayed in the graphs. A, The tract volume (TV) of the superior cerebellar peduncle (SCP) showed negative correlation with CGG length in both the fragile X–associated tremor/ataxia syndrome (FXTAS) negative (partial r23,22 = 0.33, P = .004) and FXTAS-positive (partial r23,32 = 0.24, P = .003) groups. B, The SCP fractional anisotropy (FA) showed a negative correlation with CGG repeat length in the FXTAS-positive group (partial r22,33 = 0.29, P = .001). C, The SCP also showed a negative correlation between FA and FMR1 messenger RNA in the FXTAS-positive group (partial r22,33 = 0.23, P = .003).