Adult-onset neurogenetic diseases (NGDs) with white matter abnormalities are rare and often misdiagnosed as Multiple Sclerosis (MS) due to overlapping clinical and radiological features. 1. Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL), 2. Adult-onset Leukoencephalopathy with Axonal Spheroids and Pigmented Glia (ALSP), and 3. Adult-onset Alexander Disease (AOAD) #neurology | Neurology