IRF2BPL in progressive myoclonus epilepsy – an unexpected phenotypic discovery

PME. The progressive myoclonus epilepsies (PME) are an important and distinct subgroup of genetic epilepsies. In contrast to many genetic epilepsies with a neurodevelopmental trajectory, the PMEs often follow a neurodegenerative course, which is characterized by a worsening myoclonus over time and frequently associated with cognitive decline. In a recent publication, protein-truncating variants in the intronless gene IRF2BPL were identified in two individuals with PME. However, in contrast to the relatively distinct nature of most other PME, the clinical presentation in IRF2BPL-related disorders is part of a phenotypic spectrum and emerges as one of the most usual phenotypic discoveries in the genetic epilepsies to date.

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Publications of the week – Dravet Syndrome, TBC1D24, and CSTB

Issue 6/2015. Publications from the most recent issue of Epilepsia are very prominent in this week’s selection of publications. We discuss the frequency of Dravet Syndrome, a novel family with a TBC1D24 mutation, and the role of Cystatin B (CSTB) in Juvenile Myoclonic Epilepsy. Continue reading

USP9X, Ubiquitin, and the PRICKLE interactome

PRICKLE. There are some genes implicated in human epilepsies that we have a hard time making sense of. PRICKLE1, implicated in a recessive progressive myoclonus epilepsy, is one of these genes. In a recent publication in PLoS Genetics, the interactome of the enigmatic PRICKLE proteins is explored. The authors rediscover an almost forgotten gene implicated in intellectual disability. Continue reading

GOSR2, North Sea myoclonus and the Haithabu variant

Wall Street. Between the 8th and 11th century, Haithabu (Hebedy), a Viking town in Northern Germany close to the border to Denmark was the Manhattan of its time – a flourishing trading town located at a busy shipping route at a natural short passage connecting the Eider and the Treene river, a precursor of the modern-day Kiel canal. The  Vikings used this shortcut to avoid the dangerous Skagerak when heading West on their conquests. When subsequently settling down in many regions of the North Sea coast, they carried their genetic heritage with them, including a rare variant in the GOSR2 gene, which results in a devastating epilepsy when homozygous. A recent paper in Brain now delineates the phenotype of the “North Sea” progressive myoclonus epilepsy. Continue reading

Traveling with Lennox – myoclonic jerks, West Syndrome and the 34th meridian

Where is West Syndrome? Earlier this week while browsing through the contents of Lennox’s book, I wondered where his description of West Syndrome was hidden. Lennox is very careful in reviewing the historical data on epilepsy, but for some reason, he did not mention the report by William James West, who described a particular type of epilepsy in his own son that would later be named after him. Then, when I had almost forgotten that I was on the lookout for West Syndrome, I stumbled upon it in the chapter on myoclonic seizures. Continue reading