Fig. 1.

Flowchart of patient inclusion. ALL, acute lymphoblastic leukemia; HD-MTX, high-dose methotrexate; DCOG, Dutch Childhood Oncology Group; SNP, single-nucleotide polymorphism; n, number of patients; * one patient had neurological damage before the start of HD-MTX treatment, one patients was transferred to another hospital, one patient had an adjusted protocol due to a SPINKS mutation, and one patient was initially treated otherwise due to another diagnosis