Recessive epilepsies. Dravet Syndrome is one of the most prominent genetic epilepsies and presents in the first year of life with prolonged fever-associated seizures. Haploinsufficiency of SCN1A, either through mutations or deletions, is the major cause of Dravet Syndrome. In a recent publication in the European Journal of Pediatric Neurology, two families with recessive Dravet Syndrome and biallelic SCN1A variants are reported. Let’s have a look at how to interpret these findings. Continue reading
Tag Archives: familial epilepsy
Typical versus atypical: exome sequencing in pediatric epilepsies
Exome mining. Trio exome sequencing is both easy and difficult at the same time. If you manage to identify a plausible de novo mutation, the job is pretty much done. However, if no plausible de novo is found, things can become complex very quickly. Some of the known genes for recessive disorders are quite variable and therefore difficult to interpret. Also, we know little about the overall spectrum of the recessive disorders and the plausibility of atypical cases. A recent paper in Clinical Genetics takes a comprehensive approach to the genetic basis of pediatric epilepsies by exome sequencing. The authors include the analysis of recessive and compound heterozygous variants, and they follow up on some of the biomarkers that establish the diagnosis. There are some surprising findings. Continue reading
Eyelid myoclonia with absences meets GEFS+
Running in the family. Eyelid myoclonia with absences (EMA) is a rare generalized epilepsy syndrome characterized by brief episodes of myoclonic jerks that are often accompanied by an upward deviation of the eyeballs and an extension of the head. The EEG shows generalized spike-wave discharges during these episodes, and most patients are highly photosensitive. Therefore, it would be natural to think of EMA as related to other classical generalized epilepsies including Childhood Absence Epilepsy or Juvenile Myoclonic Epilepsy. Now, a recent paper in Epilepsia shows that the families of patients with EMA tell a slightly different story. Continue reading
Traveling with Lennox – the petit mal triad
Lights on and lights out. Staring spells, petits mals, pyknolepsy and absence seizures. The brief spells that occur in patients with epilepsy have riddled neurologists for centuries. This became clear to me when Zaid Afawi and myself saw an epilepsy family in the West Bank on Sunday. When are staring spells epileptic and what kind of seizures are they? For me, this was a good opportunity to read Lennox’s thoughts on this. Eventually, after a long day under the Middle Eastern sun, I fell asleep over the chapter on absence status. Continue reading
