RESUMO
The interplay of multiple genetic factors, as opposed to monogenic inheritance, is suspected to play a role in many idiopathic generalized epilepsies. This leads to a digenic or oligogenic inheritance model, which although rather simplified, may explain at least some of the clinical observations. Here we describe a family in which the clinical phenotype in the offspring can be explained by a combination of photosensitivity and epilepsy traits that segregated independently of each other. This case history demonstrates the need to evaluate family histories in more detail in order to uncover potential clinical markers for genetic factors in complex epilepsies.
Assuntos
Epilepsia Reflexa/genética , Herança Multifatorial , Epilepsia Mioclônica Juvenil/genética , Estimulação Luminosa/efeitos adversos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , LinhagemRESUMO
PURPOSE: The interaction of genetic predisposition and the environment in the development of epilepsy is often discussed, but, aside from some animal reflex epilepsies, little evidence supports such interaction in the development of reflex epilepsy in humans. METHODS: We describe the history of a 16-year-old boy in whom photosensitive epilepsy developed after a period of weekly exposures to high-intensity light flashes. RESULTS: Both he and his clinically unaffected monozygotic twin were found to be photosensitive. CONCLUSIONS: This case report suggests that some genetic forms of human reflex epilepsy may be elicited by repeated environmental exposure to the appropriate stimulus, similar to some of the stimulus-induced epilepsies seen in animals.
Assuntos
Doenças em Gêmeos/genética , Exposição Ambiental/efeitos adversos , Epilepsia Reflexa/genética , Excitação Neurológica/genética , Estimulação Luminosa/efeitos adversos , Adolescente , Doenças em Gêmeos/diagnóstico , Eletroencefalografia/estatística & dados numéricos , Epilepsia Reflexa/diagnóstico , Predisposição Genética para Doença , Humanos , Masculino , Fenótipo , Recreação , Irmãos , Gêmeos MonozigóticosRESUMO
PURPOSE: Univerricht-Lundborg disease (ULD), with its major symptom of action myoclonus, is supposed to be very rare in the Netherlands and western Europe. We hypothesized that the syndrome may be underdiagnosed in patients with myoclonus epilepsy. METHODS: Mutation analysis of the cystatin B gene was performed in 21 cases with uncontrolled myoclonus. RESULTS: Seven of the 21 evaluated cases carried mutations in the cystatin B gene. Diagnosis of ULD was made with a mean delay of 20 years from symptom onset. CONCLUSIONS: This study from a country without previous reports of ULD suggests that underdiagnosis of the syndrome is likely. These findings also indicate that persons with juvenile-onset myoclonus epilepsy with action myoclonus should be analyzed for ULD.
