A study of ring 20 chromosome karyotype with epilepsy.
We reported a 24-year-old woman with moderate mental retardation and partial epilepsy. She developed complex partial seizures at 3 years of age and generalized tonic convulsions at 9 years. Chromosome analysis revealed that she had mosaicism (87%) of 46, XX, and r(20) (p13,q13.3). Her electroencephalogram showed bilateral 2-3 Hz sharp and wave complex over the bilateral frontopolar, and centro-parieto-occipital areas. Computed tomographic and magnetic resonance image examinations were normal. Twenty-five cases of ring 20 chromosome karyotypes (including this case) have been reported in the literature; 19 showed epilepsy, and 18 showed moderate mental retardation. Many of the patients showed growth retardation and minor malformations. The ring 20 syndrome is associated with a high incidence of epilepsy, particularly partial epilepsy. Our findings indicate that the main features of the ring 20 syndrome are partial epilepsy and mental retardation.
Department of Neuropsychiatry, Nippon Medical School, Tokyo, Japan.
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Yamadera
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Kobayashi
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Sugai
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H
Suda
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Kaneko
D000015:Abnormalities, Multiple / Q000235:genetics; D000328:Adult; D002540:Cerebral Cortex / Q000503:physiopathology; D002890:Chromosomes, Human, Pair 20; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000235:genetics* / Q000503:physiopathology; D017029:Epilepsy, Complex Partial / Q000235:genetics* / Q000503:physiopathology; D004829:Epilepsy, Generalized / Q000235:genetics* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics* / Q000503:physiopathology; D007621:Karyotyping; D012303:Ring Chromosomes; D013577:Syndrome