title: [Electroclinical characteristics of a patient with ring chromosome 20 syndrome].
abstract: BACKGROUND
  The ring chromosome 20 syndrome (r20) is a rare genetic disorder with a late diagnosis.
  
  
  METHODS
  A 17 year old boy with drug-resistant epilepsy of 14 years of evolution, which has moderate mental retardation, behavioral alterations and seizures consisting of complex non-convulsive status and generalized seizures during wakefulness, along with more subtle epileptic manifestations during sleep. Karyotype in peripheral blood showed the existence of a ring chromosome 20, whose breakpoints were p13q13.3, presenting a mosaicism 46,XY[23]/46,XY,r(20)(p13q13.3)[25].
  
  
  CONCLUSIONS
  The epileptic r20 syndrome seems to have a characteristic electroclinical phenotype and, although not pathognomonic, should be sufficient for all patients who meet a karyotype in peripheral blood, thus avoiding multiple trials with unnecessary drugs and exhaustive studies. In this sense, the study of sleep EEG may be helpful.
authors.forename: Lorena
authors.initials: L
authors.lastname: Vega-Zelaya
authors.forename: Concepción
authors.initials: C
authors.lastname: Alonso-Cerezo
authors.forename: Juan F
authors.initials: JF
authors.lastname: Quesada
authors.forename: Rafael G
authors.initials: RG
authors.lastname: Sola
authors.affiliation: Hospital Universitario de la Princesa, 28006 Madrid, Espana.
authors.forename: Jesús
authors.initials: J
authors.lastname: Pastor
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D025063:Chromosome Disorders / Q000235:genetics* / Q000503:physiopathology / Q000523:psychology; D002890:Chromosomes, Human, Pair 20 / Q000648:ultrastructure*; D004410:Dyslexia / Q000235:genetics; D004569:Electroencephalography; D004827:Epilepsy / Q000235:genetics* / Q000503:physiopathology; D004832:Epilepsy, Absence / Q000235:genetics / Q000503:physiopathology; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics; D059785:Karyotype; D008297:Male; D001523:Mental Disorders / Q000235:genetics; D009030:Mosaicism; D012303:Ring Chromosomes; D020919:Sleep Disorders, Intrinsic / Q000235:genetics / Q000503:physiopathology; D013226:Status Epilepticus / Q000235:genetics / Q000503:physiopathology; D013577:Syndrome; D014741:Video Recording