CSF1R and leukodystrophy: Thus, findings in CSF1R-related leukodystrophy patients, with heterozygous and bi-allelic variants, and in CSF1R-mutant animal models strongly indicate that a loss of microglia and macrophages in development and/or in adult life strongly affects both myelin and overall brain health, and that these effects can be at least partially abrogated through HSCT.