IDH1 and X-linked intellectual disability: High α-thalassemia X-linked intellectual disability (ATRX) expression (+ 31.6 ± 16.2 mm/year, p = 0.05, score 3/4 versus 0-2); Ki67 expression (+ 20.1 ± 11.3 mm/year, p = 0.08; score 3/4 versus 0-2); and isocitrate dehydrogenase 1 (IDH1) mutation (-28.7 ± 15 mm/year, p = 0.06) were marginally significantly associated with tumor growth (Figure 2, the results of other molecular biomarkers are shown in Supplementary Table 3).