title: Molecular biological approaches to mental retardation.
mesh_terms: D002873:Chromosome Fragility; D006801:Humans; D008607:Intellectual Disability / Q000209:etiology* / Q000235:genetics; D007926:Lesch-Nyhan Syndrome / Q000150:complications; D008967:Molecular Biology / Q000379:methods*; D010661:Phenylketonurias / Q000150:complications; D014960:X Chromosome