NF1 and glycogen storage disease VI: In multivariate analysis extramedullary disease (HR 2.46, 95% CI 1.5–4.0; p = <0.001), HMA pretreatment (HR 1.9, 95% CI 1.3-2.8; p < 0.001), presence of PTPN11 (HR 2.2, 95% CI 1.3–4.0; p = 0.006), and NF1 (HR 2.26, 95% CI 1.5–3.4; p < 0.001) mutations were identified as independent risk factors for inferior OS, whereas presence of SF3B1 mutations (HR 0.38, 95% CI 0.2–0.8; p = 0.01) remained as independent risk factor for superior OS (Table 4).