Micropolygyria, also known as polymicrogyria, polygyria, or microgyria, is a neuronal migration disorder, a developmental anomaly of the brain characterized by development of numerous small convolutions (microgyri), causing mental retardation and/or other neurological disorders. It is present in a number of specific neurological diseases, notably multiple sclerosis and Fukuyama congenital muscular dystrophy, a specific disease cause by mutation in the Fukutin gene (FKTN).