tokens: Established diagnoses include Down syndrome , Fragile X syndrome , Trisomy 8 mosaic syndrome , Trisomy 13 syndrome , Williams syndrome , Angelman syndrome , Smith–Magenis syndrome , PKU , Tuberous sclerosis , Neurofibromatosis , Sturge–Weber syndrome , Congenital rubella syndrome , the syndrome of hypoxic / ischemic perinatal brain injury , lead encephalopathy , hydrocephalus , prosencephaly , schizencephaly , and other diagnoses .