Mutations in CSF1R that cause the expression of a mutant receptor or inactivation of one Csf1r allele have been identified in rare neurodegenerative disorders: adult-onset leukodystrophy with axonal spheroids and pigmented glia (ALSP) (also known as hereditary diffuse leukoencephalopathy with axonal spheroids (HDLS)), pigmented orthochromatic leukodystrophy (POLD), and pediatric-onset leukoencephalopathy38–41. Here, CSF1R is linked to Hereditary diffuse leukoencephalopathy with axonal spheroids and pigmented glia.