[Clinical and genetic diagnosis of Dravet syndrome: report of 20 cases].
OBJECTIVE
Severe myoclonic epilepsy in infancy (SMEI; Dravet's syndrome) is a malignant epilepsy syndrome characterized by prolonged febrile hemiconvulsions or generalized seizures starting in the first year of life. Later on myoclonic, atypical absence, and complex partial seizures appear. When one of these seizure forms is lacking the syndrome of borderline SMEI (SMEB) is defined. Psychomotor delay resulting in mental retardation is observed during the second year of life. In most patients a de novo sodium channel alpha-1 subunit (SCN1A) mutation can be identified. By reviewing the clinical, laboratory, and neuroimaging data of our SMEI patients diagnosed between 2000 and 2008, we would like to share our experiences in this rare but challenging syndrome. Our results will facilitate the earlier and better diagnosis of Hungarian children with SMEI.


METHODS
Clinical, EEG, MRI and DNA mutation data of 20 SMEI patients treated in the Bethesda Children's Hospital (Budapest) were reviewed.


RESULTS
The first seizure appeared at age 6.3+/-3.0 months. At least one of the first two seizures were complex febrile seizures in 19/20 and unilateral seizures in 12/20 children. All children except for one showed hemiconvulsions at least once; all children had seizures lasting longer than 15 minutes. Eight of twenty patients had SMEB. DNA diagnostics identified an SCN1A mutation in 17 patients (6 missense, 4 nonsense, 4 frameshift, 2 splice site, 1 deletion) while 3 children had no mutation.


CONCLUSIONS
Early diagnosis of SMEI is important for the avoiding unnecessary examinations and false therapies as well as for genetic counselling. Typical symptoms of SMEI are early and prolonged febrile hemiconvulsions with neurological symptoms, mental retardation and secondary seizure types later on. The presence of an SCN1A mutation supports the diagnosis. We propose the availability of molecular diagnostics and stiripentol therapy for SMEI children in Hungary
Siegler
Zsuzsa
Z
Magyarországi Református Egyház Bethesda Gyermekkórháza, Neurol6giai Osztály, Budapest. siegler.zsuzsa@bethesda.hu
Neuwirth
Magdolna
M
Hegyi
Márta
M
Paraicz
Eva
E
Pálmafy
Beatrix
B
Tegzes
Andrea
A
Barsi
Péter
P
Karcagi
Veronika
V
Claes
Lieve
L
De Jonghe
Peter
P
Herczegfalvi
Agnes
A
Fogarasi
András
A
D000293:Adolescent; D000927:Anticonvulsants / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D004148:Dioxolanes / Q000627:therapeutic use; D004569:Electroencephalography; D004831:Epilepsies, Myoclonic / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics*; D004832:Epilepsy, Absence / Q000175:diagnosis / Q000235:genetics; D017029:Epilepsy, Complex Partial / Q000175:diagnosis / Q000235:genetics; D005260:Female; D006801:Humans; D006814:Hungary / Q000453:epidemiology; D007223:Infant; D008607:Intellectual Disability / Q000209:etiology; D008279:Magnetic Resonance Imaging; D008297:Male; D009154:Mutation; D020190:Myoclonic Epilepsy, Juvenile / Q000175:diagnosis / Q000235:genetics; D062550:NAV1.1 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins / Q000235:genetics*; D011596:Psychomotor Disorders / Q000150:complications / Q000209:etiology; D003294:Seizures, Febrile / Q000209:etiology; D015222:Sodium Channels / Q000235:genetics*
D000927:Anticonvulsants; D004148:Dioxolanes; D062550:NAV1.1 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins; C568242:SCN1A protein, human; D015222:Sodium Channels; C021092:stiripentol