In this study, we described and analyzed adult patients with pediatric-type diffuse gliomas, particularly diffuse astrocytoma, MYB- or MYBL1-altered, diffuse midline glioma, H3 K27-altered, and diffuse pediatric-type high-grade glioma, H3-wildtype and IDH-wildtype. The gene discussed is IDH1; the disease is diffuse astrocytoma.