title: Severe mental retardation due to maternal phenylketonuria.
mesh_terms: D004200:Diseases in Twins; D005260:Female; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000209:etiology*; D008297:Male; D008431:Maternal-Fetal Exchange; D010661:Phenylketonurias / Q000150:complications / Q000235:genetics*; D011247:Pregnancy; D014429:Twins, Dizygotic