The propositus of this report presents a peculiar dysmorphic syndrome associated with severe mental retardation and epileptic attacks. Morphological stigmata include a round, fatty face with large, somewhat protruding tongue, large normally formed ears, relative microcephaly, abundant abdominal fat, dwarfism with hyperkyphosis and short neck. Analogous phenotypic abnormalities were present in the mother and a maternal cousin. The clinical and familial findings in this apparently rare mental retardation syndrome with apparently X-linked dominant or autosomal dominant inheritance with variable expression and penetrance are discussed.