Vega-Zelaya Lorena, Alonso-Cerezo Concepción, Quesada Juan F, Sola Rafael G, Pastor Jesús
Hospital Universitario de la Princesa, 28006 Madrid, Espana.
Rev Neurol. 2014 May 16;58(10):450-4.
The ring chromosome 20 syndrome (r20) is a rare genetic disorder with a late diagnosis.
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].
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.
20号环状染色体综合征（r20）是一种罕见的遗传性疾病，诊断较晚。
一名17岁男孩，患有14年病程的耐药性癫痫，伴有中度智力障碍、行为改变以及清醒时出现复杂非惊厥性癫痫持续状态和全身性癫痫发作，睡眠期间还有更细微的癫痫表现。外周血核型显示存在一条20号环状染色体，其断点为p13q13.3，呈现46,XY[23]/46,XY,r(20)(p13q13.3)[25]的嵌合体。
癫痫性r20综合征似乎具有特征性的电临床表型，尽管不具有诊断特异性，但对于所有外周血核型符合的患者来说应该足够了，从而避免进行多次不必要的药物试验和详尽检查。从这个意义上讲，睡眠脑电图研究可能会有所帮助。
