ABCD1 and X-linked adrenoleukodystrophy: X-linked adrenoleukodystrophy is a neurodegenerative disorder caused by mutations in ABCD1. By applying a vascular model to conventional MR perfusion imaging, Lauer et al. demonstrate that ABCD1 deficiency causes alterations in microvascular flow in white matter areas and developmental stages with the highest probability for conversion to cerebral disease.