Obesity and hypotonia in association with delayed mental development, characteristic facies, and slender hands and feet. The syndrome is divided into two forms: one which is manifested by the symptoms as outlined by Cohen and the other characterized by chorioretinal dystrophy, leukopenia, and lack of obesity, known as the Norio syndrome. The syndrome is sometimes is referred to as the Pepper syndrome after the affected family. Mirhosseini-Holmes-Walton and Cohen syndrome share many common characteristics