GSTM1 and Schnyder corneal dystrophy: Consequently, by calculating r*FA,Hb2, the proportion of variance in *FA explained by Hb, we observed that in control and non-SCD for the WMSs reported in Table 2, Hb accounts for up to 26% (right thalamus and right amygdala) of the variance in *FA, and up to 21% (left thalamus and left parahippocampal gyrus) in the case of controls with SCD patients.