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.
Yamadera
H
H
Department of Neuropsychiatry, Nippon Medical School, Tokyo, Japan.
Kobayashi
K
K
Sugai
K
K
Suda
H
H
Kaneko
S
S
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