Abstracts

RATIONALE: The reason of origin of ring chromosomes is unknown. In the formation of ringchromosomes both ends (telomers) of a chromosome are fused. This causes a loss of gene sequences and could play an important rule in epileptogenesis. METHODS: We analysed retrospectively 5 patients from our institution (3 boys: 2,5 and 15 years old; 2 girls: 9 and 11 years old) and 24 patients described in literature. RESULTS: In our patients the seizure onset was in the first year of life (3x with 6 months, 2x with 10 months). In two cases we diagnosed infantile spasms, in the course complex-focal and secondarily generalized seizure with a lower frequency after infancy. 4 of our 5 patients had a severe mental retardation ( one had only a mild mental retardation). We observed no facial dysmorphia signs or abnormalities on CT or MRI scans of the brain. There were no common appearances in the EEG patterns, and not many epilepsy typical changes. All patients from literature with ringchromosome 14 developed seizures during first year of life. In some cases the authors report the lack of dysmorphia signs and normal cranial CT or MRI scans. CONCLUSIONS: 1.In patients with ringchromosome 14 an interesting asociation with epileptic seizures does exist, according to literature and our 5 patients. 2. In most cases we found focal seizures with a seizure onset in the first year of life. 3. Focal-cortical dysplasias or severe brain abnormalities could be excluded as reason for epilepsy. 4.Up to now there are no publications which describe genes in the telomer region of chromosome 14 and relation to epileptogenesis 5.Moleculargenetic examinations in the telomer region of chromosome 14 could be very important for the understanding of genetic factors in epilepsy.