TET3 and fragile X syndrome: To rule out the possibility that the differential gene expression we observed between the two UFM carriers, the control and the FXS lines is due to the coincidental aberrant expression of these genes in healthy controls and FXS cells, we confirmed in two, unrelated, healthy control fibroblast lines that expression levels of TET3 were similar to the level of the healthy and FXS control cells we used for the initial comparisons (Supplemental Fig. 2).