Epilepsy Genetics Spycraft, UGDH, and Mardi Gras

The gene on your hand. We should never apologize for telling people about genetic epilepsies, we should apologize for not telling people enough about it. At the 2024 Mardi Gras celebration of the Epilepsy Foundation of Eastern Pennsylvania, I had the honor of being given the Charley and Peggy Roach Founders’ & Eric Burton Osberg Award, also known as “Philadelphia Epilepsy Medical Professional of the Year”. I am quite sure that there must have been a data entry error or that the selection committee slipped in the line when they made this decision. Many of our epilepsy nurses, nurse practitioners, EEG techs, researchers, and physicians caring for people with epilepsy in Eastern PA would have been much more eligible for this honor than myself. However, given this unlikely opportunity, I used my moment on the stage to highlight our team and dedicate this award to Connor Maule, one of my patients who passed away from a rare genetic epilepsy in 2021. To honor Connor and epilepsy patients alike, I asked the audience to take a gene home with them – signing their hands with a gene name using a sharpie.

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SCN1A in FinnGen – epilepsy, dementia, and type 2 diabetes

Isolates. Last week, the FinnGen biobank went live, and Nature dedicated an entire issue to the launch of this initiative. In brief, FinnGen is a large Finnish research project providing genomic and clinical data from a Finnish biobank with the aim to provide new insights into human disease. Finland is an isolated population, which offers unique insights into the role of rare variants in disease. When I checked the FinnGen database for association with SCN1A, I was surprised that three missense variants have been associated with various diseases. Here is what a founder population can tell us about the various roles of SCN1A in human disease. Continue reading

Papers of the week – GABRA1 and STXBP1 in Dravet, gene therapy & synonymous mutations in cancers

FASTA, FASTQ, SAM, BAM, BWA, GC, GATK, IGV. Phew. Day 2 at the EuroEPINOMICS bioinformatics workshop in Leuven. Usually my work starts after the initial NGS raw data quality control and mapping procedures. Today’s topics are supposed to improve my understanding of sequencing analysis and NGS data interpretation. While we are still struggling, other scientists have done their home work already. Here are some of the remarkable publications from this week.


Biologists, physicians and computer scientist at the EuroEPINOMICS bioinformatics workshop 2014 in Leuven

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GPHN deletions in IGE and mutation-dependent recessive inheritance

Bild1Living in Cologne is a little tough at the moment. Currently, we are in the middle of the Cologne Carnival, the world’s oldest carnival, which started in 1829. Until the upcoming Wednesday the entire city is one big festival. In addition to the 1 million Cologne citizens probably another million tourists will join. Due to this (positive) distraction I will write less than usual. However, I still consider this week’s publications noteworthy. Continue reading

Papers of the week – 15q11 duplications, Olig1 & Automated decision-making


A productive week in epilepsy genetics.  Scientists and editors were certainly busy this week reporting novel variants and deletions as well the experimental and statistical advances for their interpretation.

A de novo GRIN2A missensmutation in early-onset epileptic encephalopathy. We and others have associated variants affecting the GRIN2A gene with a range of childhood focal epilepsy syndromes. Continue reading

Chutzpah, Zen and Fahrvernügen – the 2013 Sde Boker workshop

Desert Dessert. Cold temperatures, streets closed because of snow – this is not what you expect when traveling to Israel. You also do not expect to have the chance to taste traditional Bedouin food and to see a beautiful canyon every morning. The biggest surprise is that you do not expect this during a workshop. From Dec 12-15th, the European epilepsy genetic community gathered in Be’er Sheva and Sde Boker, Israel for a combined epilepsy genetics workshop and a Young Researcher Meeting. This is a brief attempt to capture the atmosphere of this workshop for everybody who could not attend. By the way, “desert dessert” is a port wine produced in the Negev desert.

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15q11.2 – the microdeletion spectre

Genetic mirage. We look at genetic variants all the time. There are few genetic variants that stare back at us. 15q11.2 is one these variants, facing us with the constant question how we define and perceive genetic risk. Not because of its pathogenicity, but because of the confusion that it causes. Continue reading

Of angels and interneurons

Angelman Syndrome and UBE3A. Angelman Syndrome is a severe neurodevelopmental disorder characterized by intellectual disability, typical facial features and a usually happy demeanor. Patients with Angelman Syndrome usually do not acquire active speech and often show a characteristic, atactic gait. Also, patients with Angelman Syndrome have a characteristic EEG pattern and many children have seizures. Angelman Syndrome is a genetic disorder due to loss of function of UBE3A, a ubiquitin ligase expressed in the CNS. Ubiquitin ligases are the bin collectors of the cell. By attaching ubiquitin to proteins, proteins are labelled for cellular degradation. How a malfunction of a cellular garbage truck causes such a complex neurodevelopmental disorder is poorly understood. A recent study, however, points out an important role for interneurons…. Continue reading

FAME – when phenotypes cross over but chromosomes don’t

Crompton and colleagues recently published the clinical and genetic description of a large family with Familial Adult Myoclonic Epilepsy (FAME).  This phenotype is particularly interesting since it provides some insight into how neurologists conceptualize twitches and jerks.  It is also a good example that large families do not necessarily result in a narrow linkage region, particularly when centromeric regions are involved.

What is myoclonus?  Despite usually mentioned in the context of epilepsy, most people are inherently familiar with myoclonus. Most of us “twitch” when we fall asleep and sometimes experience this twitch as part of a dream.  These episodes are entirely normal and are called hypnic jerks, but they give people a good idea of what a sudden, brief, shocklike, involuntary movement caused by muscular contraction or inhibition would feel like.  Myoclonus in the setting of epilepsy is usually mentioned as part of a Juvenile Myoclonic Epilepsy (JME) or Progressive Myoclonus Epilepsy (PME).  Please note that both epilepsies use different endings to describe the twitch (“-us” vs. “–ic”).  This is mainly convention.  Basically, myoclonus is a brief shock-like twitch, which can affect almost every part of the body and can be due to dysfunctions in various regions in the Central Nervous System.

The neuroanatomy of twitching.  A motor command from the cerebral cortex has to pass through several steps prior to execution.  For example, the simple command of tapping a finger on the table surface is prepared by the cortex through several loops before being sent down your spine.  Accordingly, myoclonus can arise from different parts in the brain.  (1) The cortical myoclonus is due to a purely cortical source and can be seen in many forms of symptomatic myoclonus.  (2) The cortico-subcortical myoclonus is due to feedback from the cortex to other brain areas. This is the myoclonus we see in patients with JME.  Both variants may be seen on EEG since the cortex is involved.  (3) The subcortical-supraspinal myoclonus is generated in the brain stem or below and is responsible for phenomena such as hyperekplexia or startle disease.   Some forms of hyperekplexia, literally “exaggerated surprise”, are due to mutations in genes involved in glycinergic transmission and can be found in some isolated communities such as the Jumping Frenchmen of Maine.  (4) Finally, there is also spinal and peripheral myoclonus.

FAME – epilepsy or movement disorder?  Familial Adult Myoclonic Epilepsy (FAME) is an enigmatic familial disorder with the triad of myoclonus, tremor and seizures.  Several families have been described and two loci on 8q23.3-8q24.11 and 2p11.1-q212.2 for FAME have been established.  The underlying genes are still unknown.  Crompton and colleagues no describe a large six-generation family with FAME in Australia/New Zealand.  The familial disease usually starts with tremor in early adulthood in the affected family members, even though a wide range of age of onset is observed. Interestingly, only a quarter of all affected family members had seizures, which is in contrast to previous studies.  Therefore, FAME may actually be better characterized as a movement disorder with concomitant seizures rather than a familial epilepsy syndrome.  The authors also point out the difficulties distinguishing FAME from the much more common essential tremor (ET).  In particular, the well-described response to β-blockers seen in patients with ET can also be observed in some family members.

Figure 1. The candidate gene landscape of the chr2 FAME region. All genes were searched for the number of hits in PubMed for the listed search terms in an automated fashion. As usual in large linkage intervals, only few genes are known in the context of neurological disorders, while most genes are unknown.

The genetics of FAME.  Crossovers during meiosis usually lead to a progressive narrowing of the linkage interval in familial disorders.  However, the lack of crossover events leads to very large linkage intervals even in very extended families.  The family described by Crompton et al. links to the pericentromeric region of chromosome 2.  Pericentromeric regions usually have a low frequency of crossover events, and this phenomenon has also delayed the identification of other familial epilepsies such as Benign Familial Infantile Seizures with mutations in PRRT2.  The linkage region contains almost 100 genes and Figure 1 shows the “candidate gene landscape” in this region.  While some genes clearly classify as top candidate genes, the majority of the genes in this region are unknown in the context of epilepsy. Therefore, identification of the FAME gene will be exciting and provide us with novel insight on how genetic alterations may produce combined neurological phenotypes.