Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 5 2 2020 08 30 51 54 Ghazaleh Jamalipour Soufi Department of Radiology, Isfahan University of Medical Sciences, Isfahan, Iran. Siavash Iravani School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. 2019 12 29 2020 04 02 Pelizaeus-Merzbacher Disease (PMD), as a rare genetically x-linked leukodystrophy, is a disorder of proteolipid protein expression in myelin formation. This disorder is clinically presented by neurodevelopmental delay and abnormal pendular eye movements. The responsible gene for this disorder is the proteolipid protein gene (PLP1). Our case was a oneyear- old boy referred to the radiology department for evaluating the Central Nervous System (CNS) development by brain Magnetic Resonance Imaging (MRI). Clinically, he demonstrated neuro-developmental delay symptoms. The brain MRI results indicated a diffuse lack of normal white matter myelination. This case report should be considered about the possibility of PMD in the brain MRI of patients who present a diffuse arrest of normal white matter myelination. https://crcp.tums.ac.ir/index.php/crcp/article/view/324 https://crcp.tums.ac.ir/index.php/crcp/article/download/324/353