A novel de novo SCN1A missense mutation in Severe Myoclonic Epilepsy Borderland.
In this report we describe a novel missense SCN1A mutation in a patient affected by Severe Myoclonic Epilepsy Borderland (SMEB). This three and a half year-old female patient experienced prolonged febrile seizures at the age of 14 months, followed by generalized tonic-clonic seizures, atonic seizures, atypical absences almost in a cluster and triggered by fever. Cognitive and motor development was normal. The case was suggestive for SMEB. SCN1A analysis revealed an unknown de novo point mutation: a heterozygous replacement of nucleotide G with nucleotide T in position 4183 of the coding region of the gene (c.4183 G>T) in exon 21. This mutation causes the replacement of aspartic acid with tyrosine in 1395 (p.D1396Y). Even if other SCN1A missense mutations localized in the same region are associated to SMEB, a definite genotype-phenotype correlation has not yet been found, probably because other factors are involved in the pathogenesis of this type of epilepsy.
Division of Neurology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy. nicola.specchio@opbg.net
Nicola
N
Specchio
Marina
M
Trivisano
Martina
M
Balestri
Elena
E
Gennaro
Luigi M
LM
Specchio
Lucia
L
Fusco
Federico
F
Zara
Federico
F
Vigevano
D002675:Child, Preschool; D004569:Electroencephalography; D004831:Epilepsies, Myoclonic / Q000175:diagnosis / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D020125:Mutation, Missense; D062550:NAV1.1 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins / Q000235:genetics*; D010641:Phenotype; D012720:Severity of Illness Index; D015222:Sodium Channels / Q000235:genetics*
D062550:NAV1.1 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins; C568242:SCN1A protein, human; D015222:Sodium Channels