Disorders with prominent posterior fossa involvement.

Inherited white matter disorders include a wide range of disorders of various origins with distinct genetic, pathophysiologic, and metabolic backgrounds. Although most of these diseases have nonspecific clinical and radiologic features, some display distinct clinical and/or imaging (magnetic resonance imaging, MRI) characteristics that might suggest the causative gene. Recent advances in genetic testing allow assessing gene panels that include several hundred genes; however, an MRI-based diagnostic approach is important to narrow the choice of candidate genes, particularly in countries where these techniques are not available. Indeed, white matter disorders with prominent posterior fossa involvement present specific MRI (and clinical) phenotypes that can directly orient the diagnosis. This chapter describes the main genetic disorders with posterior fossa involvement and discusses diagnostic strategies.