Muscle-Eye-Brain disease (MEB), officially known as muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), is an inherited disorder caused by a dysfunctional enzyme called protein O-mannose beta-1,2-N-acetylglucosaminyltransferase. This condition is characterized with muscle weakness at birth, eye and vision abnormalities, including severe nearsightedness and brain abnormalities. Individuals with MEB usually have developmental delay and intellectual disability. Some affected individuals may learn how to walk and say a few words. There is no cure for MEB; however medical surveillance and care may help to improve some symptoms and overall condition of life. Life expectancy ranges from childhood into adolescence. MEB is caused by pathogenic variants in the POMGNT1 gene.