The adult motor phenotype of Dravet syndrome is Associated with Mutation of the STXBP1 Gene and Responds Well to Cannabidiol Treatment

Dravet syndrome is a terrible disease generally caused by mutations of the SCN1A gene. Recently others genes such as STXBP1 have been involved in the pathogenesis of the disease. The STXBP1 mutation in patients with Dravet Syndrome may additionally causes several parkinsonian features usually attributed to carriers of the SCN1A mutation. Management continues to be difficult; that is why Cannabidiol emerged as valid option for treatment of this condition.

Elevated Cerebrospinal Fluid Protein in POLG-Related Epilepsy: Diagnostic and Prognostic Implications

SIGNIFICANCE: Our results indicate that there is disruption of the blood brain barrier in POLG-related disease, as evidenced by a raised cerebrospinal fluid protein and a raised CSF/serum ratio of albumin. We also find that raised cerebrospinal fluid protein is a common finding in patients with POLG disease. Our data suggest that the presence of blood brain barrier dysfunction predicts a poorer outcome, and elevated cerebrospinal fluid protein may therefore be an additional biomarker both for early diagnosis and to identify those at high risk of developing epilepsy.

OBJECTIVE: Epilepsy is common in individuals with mutations in POLG, the gene encoding the catalytic subunit of the mitochondrial DNA polymerase gamma. Early recognition and aggressive seizure management are crucial for patient survival. Disruption of the blood-brain barrier (BBB) is implicated in various neurological disorders including epilepsy. The aim of this study was to assess whether POLG-related disease is associated with BBB dysfunction and what clinical implications this has for patients.

METHODS: Our retrospective study used data from 83 patients with pathogenic POLG mutations from 4 countries–Norway, Sweden, Finland, and the United Kingdom. Data were collected using a structured questionnaire. We used the presence of raised cerebrospinal fluid (CSF) protein and a raised CSF/serum ratio of albumin (Q-alb) to evaluate the integrity of the blood-CSF barrier.

RESULTS: Raised CSF protein was found in 70% of patients (n = 58/83) and appeared to be associated with the most severe phenotypes. In those in whom it was measured, the Q-alb ratio was markedly elevated (n = 18). The majority of those with epilepsy (n = 50/66, 76%) had raised CSF protein, and this preceded seizure debut in 75% (n = 15/20). The median survival time from symptom onset for those with raised CSF protein was decreased (13 months) compared to those with normal CSF protein (32 months).

Clinical trial: Rolandic Epilepsy Genomewide Association International Study (REGAIN)

Approximately 25% of child patients have Rolandic Epilepsy or RE, also known as Benign Epilepsy with Centrotemporal Spikes (BECTS). RE has a complex genetic basis, probably made up of combinations of susceptibility variants in different genes. Children with RE quite often have other symptoms that affect their speech, attention, reading ability or coordination. The goal of this study is to find the genetic basis for susceptibility to seizures and associated comorbidities for RE using genomewide association approaches.

We know that RE has a genetic basis and we recently discovered the genetic cause of the EEG pattern seen in RE. The goal of REGAIN is to now find the genetic basis for susceptibility to seizures and the associated symptoms above. Our hope is to be able to improve diagnosis and understand why each child with RE is different, and perhaps point us towards new treatments that are more effective and have fewer side effects.

We will compare the genetic code of 3,000 children with RE against a similar number of people not affected by epilepsy. With the proposed large sample of participants, we will be able to pinpoint the exact changes that might lead to seizures or attention problems for example. Learning the genetic basis for these problems will deepen our understanding of the mechanisms and lead to new treatments or cures.

Estimated study start date: June 1, 2018
Estimated study completion date: December 31, 200

Eligibility Criteria

Ages Eligible for Study: 6 Years to 25 Years (Child, Adult)
Sexes Eligible for Study: All
Accepts Healthy Volunteers: No
Sampling Method: Non-Probability Sample

Inclusion Criteria:

  • Diagnosis of Rolandic Epilepsy in accordance with the following international criteria:
    • Age of first afebrile seizure 3-12 years
    • Seizures comprising focal sensorimotor seizures affecting the vocal tract and face, with or without involvement of the arm
    • Predominant sleep-related seizures
    • EEG interictal centro-temporal spikes with normal background
  • Current age 6-25 years

 

Exclusion Criteria:

  • No history of focal seizure
  • Normal EEG or abnormal background features on EEG
  • Known structural causes (stroke, tuberous sclerosis, infection, post-infectious or metabolic)
  • Primary diagnosis of autism or global learning disability
  • Focal central neurological deficit on clinical exam,
  • Unable to provide informed consent
  • Unable to provide blood sample

Variability in Gene-Sequencing Panels Could Mean Missed Early-Life Epilepsy Diagnoses: Work Featuring CURE Grantee Annapurna Poduri

Epilepsy genetics is an emerging field with increasing therapeutic implications resulting from genetic findings. Despite an overall enthusiasm for precision medicine in epilepsy and other disciplines, there remains no consensus on the approach to genetic testing. A recent study by Berg et al demonstrated a relatively similar diagnostic yield of epilepsy next-generation sequencing (NGS) gene panels compared with whole-exome sequencing (27% vs 33%). Although the utility of NGS panels are consistently demonstrated to our knowledge, no study has systematically evaluated the variability in genes tested among clinically available NGS panels. We compared the potential diagnostic yield of commercially available NGS epilepsy panels to detect the genetic findings identified in a recently published cohort of early-life epilepsy.

Dr. Annapurna Poduri [a CURE grantee] and colleagues from Boston Children’s Hospital compared 10 commercially available NGS gene panels from three major vendors (Athena Diagnostics, Ambry Genetics and GeneDx).

Genetic Literacy Series: Primer Part 2—Paradigm Shifts in Epilepsy Genetics

This is the second of a 2?part primer on the genetics of the epilepsies within the Genetic Literacy Series of the Genetics Commission of the International League Against Epilepsy.

In Part 1, we covered types of genetic variation, inheritance patterns, and their relationship to disease. In Part 2, we apply these basic principles to the case of a young boy with epileptic encephalopathy and ask 3 important questions: (1) Is the gene in question an established genetic etiology for epilepsy? (2) Is the variant in this particular gene pathogenic by established variant interpretation criteria? (3) Is the variant considered causative in the clinical context? These questions are considered and then answered for the clinical case in question.

Epilepsy Research Findings: May 2018

This month I would like to share with you several promising treatment and diagnostic advances, and research discoveries. The FDA recently recommended supporting the approval of the New Drug Application for cannabidiol-based drug Epidiolex and also approved Medtronic’s deep brain stimulation therapy for drug-resistant epilepsy. Recent research has also provided the promise of new genetic insight for children with epileptic encephalopathy, and has brought us closer to understanding how to repair a “leaky” blood-brain barrier associated with epilepsy. In contrast to these exciting results, we have also learned that individuals with epilepsy are at an increased risk of dying from suicide and accidents, and a new study has highlighted the high direct costs associated with epilepsy for children with the disorder.

Summaries of all highlighted studies follow below. I’ve organized the findings into four categories: Treatment Advances, Diagnostic Advances, Research Discoveries, and Also Notable.

TREATMENT ADVANCES

GW Pharmaceuticals and U.S. Subsidiary Greenwich Biosciences Announces FDA Advisory Committee Unanimous Recommendation of Support for Epidiolex

GW Pharmaceuticals plc, along with its U.S. subsidiary Greenwich Biosciences, announced that the Peripheral and Central Nervous System Drugs Advisory Committee of the U.S. Food and Drug Administration unanimously recommended supporting the approval of the New Drug Application (NDA) for the investigational cannabidiol oral solution (CBD), also known as Epidiolex®, for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) and Dravet syndrome in patients two years of age and older. If approved, Epidiolex would be the first pharmaceutical formulation of purified, plant-based CBD.

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Medtronic Receives FDA Approval for Deep Brain Stimulation Therapy for Medically Refractory Epilepsy

Medtronic plc, the global leader in medical technology, announced that the U.S. Food and Drug Administration has granted premarket approval for Medtronic’s Deep Brain Stimulation (DBS) therapy as adjunctive treatment for reducing the frequency of partial-onset seizures in individuals 18 years of age or older who are refractory or drug-resistant to three or more antiepileptic medications. DBS therapy for epilepsy delivers controlled electrical pulses to a target in the brain called the anterior nucleus of the thalamus, which is part of a network involved in seizures.

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Zynerba Pharmaceuticals Announces Twelve Month Data from STAR 2 Study in Patients with Focal Seizures

Zynerba Pharmaceuticals, Inc reported new longer term open label clinical data from its STAR 2 Study in patients with focal seizures. “The data continues to suggest that focal seizures may be reduced with longer-term exposure to transdermally-delivered CBD,” said Dr. Liza Squires, Zynerba’s Chief Medical Officer. “In this population of patients, the use of ZYN002 for an additional 12 months in STAR 2 was well tolerated and appeared to result in clinically meaningful seizure reductions both across and within the originally randomized STAR 1 groups.”

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Zynerba Pharmaceuticals Initiates Open-Label Phase 2 Trial of ZYN002 in Developmental and Epileptic Encephalopathies

Zynerba Pharmaceuticals announced that it has initiated the Phase 2 BELIEVE 1 clinical trial, an open label study to assess the safety and efficacy of ZYN002 administered as a transdermal gel to children and adolescents with developmental and epileptic encephalopathy.

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DIAGNOSTIC ADVANCES

New Testing Provides Better Information for Parents of Children with Epileptic Encephalopathy

Advances in genetic testing offer new insights to parents who have a child with a rare but serious form of epilepsy, epileptic encephalopathy. New ways of sequencing the human genome mean geneticists and genetic counselors have much more to say to parents who wonder if future children might carry the disease, says Dr. Heather Mefford, Associate Professor of Pediatrics (genetic medicine) at University of Washington School of Medicine and Deputy Scientific Director of the Brotman Baty Institute for Precision Medicine, co-senior author of findings published in the New England Journal of Medicine.

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RESEARCH DISCOVERIES

Repairing a Leaky Blood-Brain Barrier in Epilepsy

In a study of rodent brain capillaries published in the Journal of Neuroscience, Björn Bauer and colleagues identified a seizure-triggered pathway that contributes to blood-brain barrier dysfunction in epilepsy. The blood-brain barrier is a filtering mechanism that lets nutrients into the brain but keeps toxins out. Understanding how a “leaky” blood-brain barrier can lead to seizures is necessary to develop strategies to plug the leak.

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Hope for New Treatment of Severe Epilepsy

Researchers at Lund University in Sweden succeeded in reducing epileptic activity in the hippocampus. In many severe cases of epilepsy, this is the part of the brain where epileptic seizures start. The researchers used a method known as chemogenetics, which enables them to reduce activity in the specific areas and nerve cells involved in an epileptic seizure, whereas other parts and cells in the body remain unaffected. This is in contrast to current drugs that affect more or less all parts and cells of the body, potentially leading to side-effects.

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Epilepsy Does Not Impact Likelihood of Pregnancy

Women with epilepsy, without previous infertility and related disorders, were as likely to conceive as their counterparts without epilepsy, according to findings recently published in JAMA Neurology. Dr. Page B. Pennell and colleagues found that 60.7% of women with epilepsy became pregnant versus 60.2% of the control group without epilepsy.

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Increased Risk of Suicide and Accidental Death Found for People with Epilepsy

A new study has shown that people diagnosed with epilepsy in England and Wales are at increased risk of dying from suicide and accidents. Though the risks of dying from suicide and accidents for people with epilepsy are low in absolute terms (0.3-0.5%), they are higher than in people without epilepsy, says Dr. Hayley Gorton from The University of Manchester.

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ALSO NOTABLE

What Modern Day Challenges Affect Epilepsy Treatment?

Researchers recently published an article in The Lancet Neurology discussing the difficulties facing seizure detection in patients with epilepsy. In a recent study, Christian Elger and Christian Hoppe determined that a key challenge facing patients is that over 50% of patients under-report the number of seizures they experience, which has a serious impact on how well doctors are able to determine what treatments are most suitable for them. This also calls into question much of the previously published research on epilepsy treatments.

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Study Finds a High Direct Cost of Epilepsy in Children

A study of children aged 17 years using data from the Medical Expenditure Panel Survey-Household Component found that medical expenditure among children with epilepsy is high. The high expenditure is essentially driven not only by inpatient expenditure but also by home healthcare, outpatient, and medication healthcare expenditures.

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CURE Discovery: Genetic Research Finds Potential Alternatives to Brain Surgery for Children with Cortical Dysplasia

A Potential Alternative is Already in Clinical Trial

Recent research by CURE grantee Dr. Jeong Ho Lee of the Korea Advanced Institute of Science and Technology has shed important light on the genetic mutations that lead to focal cortical dysplasia, a severe form of pediatric epilepsy that inadequately responds to available treatment options. Genetic mutations were found in the brain tissue of individuals affected by a particular subtype of focal cortical dysplasia (focal cortical dysplasia type II) that is characterized by brain abnormalities, leading to seizures and epilepsy.

Conventional genetic testing methods to identify genetic mutations in those with epilepsy often use blood or saliva from patients. However, these latest results from Dr. Lee and his team suggest that certain epilepsy-related gene mutations may only be detectable when brain tissue is analyzed.

Brain-Only Mutations in Genes that Cause Focal Cortical Dysplasia

By comparing blood and saliva samples to samples of brain tissue from a group of 40 individuals who had previously undergone brain surgery for focal cortical dysplasia type II, Dr. Lee and his team found that a significant number of these individuals (12.5%) had brain-only mutations in genes TSC1 and TSC2. Together with the previous pioneering work of his team to identify brain-only mutations in the MTOR gene in individuals with focal cortical dysplasia type II, they revealed that brain-only mutations in genes within the mTOR brain signaling pathway (including the genes TSC1, TSC2 and MTOR) are found in up to 30% of individuals with focal cortical dysplasia. The fact that these mutations were found only in the brain means that these mutations would be undetectable by conventional genetic testing methods, suggesting that investigation of brain-only mutations should be explored to a greater extent.

In addition to identifying brain-only mutations leading to focal cortical dysplasia, Dr. Lee and his team also addressed the current lack of adequate animal models to better study the disorder. The team was able to successfully recreate the brain-only mutations in genes TSC1 and TSC2 in developing mice, providing a much-needed animal model for further examination of the ways in which gene mutations can lead to focal cortical dysplasia type II.

Clinical Trials for the Treatment of Focal Cortical Dysplasia

Furthermore, the team provided evidence that mTOR inhibitors, such as rapamycin or everolimus, are promising anti-epileptic drugs for the treatment of focal cortical dysplasia. In fact, everolimus is currently under phase II clinical trial for the treatment of focal cortical dysplasia.

As noted by Dr. Lee, because focal cortical dysplasia is a drug-resistant epilepsy, many children with the disorder require invasive brain surgery as treatment. However, even in cases where surgery is performed, up to 40% of these children may still have seizures. By identifying genes associated with focal cortical dysplasia as well as creating a new way of studying the genetic mechanisms behind the disorder, Dr. Lee and his team have made progress towards the creation of novel, non-surgical targets at which to aim treatments for this devastating form of drug-resistant childhood epilepsy.

[1] Lim et al. Somatic mutations in TSC1 and TSC2 cause focal cortical dysplasia. Am J Human Genet 2017; 100(3):454-472.
[2] Guerrini et al. Diagnostic methods and treatment options for focal cortical dysplasia. Epilepsia 2015; 56(11):1669-86.
[3] Gaitanis and Donahue. Focal cortical dysplasia. Ped Neurol 2013; 49:79-87.
[4] Poduri et al. Genetic testing in the epilepsies – developments and dilemmas. Nat Rev Neurol 2014; 10(5):293-299.
[5] Lim et al. Brain somatic mutations in MTOR cause focal cortical dysplasia type II leading to intractable epilepsy. Nat Med 2015; 21(4):395-400.

New Testing Provides Better Information for Parents of Children with Epileptic Encephalopathy

Advances in genetic testing offer new insights to parents who have a child with a rare but serious form of epilepsy, epileptic encephalopathy (EE), found in one of about every 2,000 births and characterized by developmental disabilities as well as horrible seizures.

“New ways of sequencing the human genome mean geneticists and genetic counselors have much more to say to parents who wonder if future children might carry the disease,” says Dr. Heather Mefford, associate professor of pediatrics (genetic medicine) at University of Washington School of Medicine and Deputy Scientific Director of the Brotman Baty Institute for Precision Medicine, co-senior author of findingspublished this week in the New England Journal of Medicine.

A big question from any parent of a child with EE is, “What are the odds that our other children might have this condition?” For decades, parents whose child had epilepsy were told there’s a 1 to 5 percent chance that other children might inherit the mutation. This was based on clinical evidence – the numbers of reoccurrences physicians saw in the clinic.

But armed with more precise testing, the geneticists found parental mosaicism that wasn’t easily detected before in about 10 percent of families, putting these families at higher risk of passing the mutation to another child. What this means in practical terms is that this small group probably accounts for most of the reoccurrences. For some parents, there’s good news: if this parental mosaicism was not detected, your odds of having another such child with epilepsy could be much less than 1 percent.

Critical Review: Can Mutation?Mediated Effects Occurring Early in Development Cause Long?Term Seizure Susceptibility in Genetic Generalized Epilepsies?

Summary: Epilepsy has a strong genetic component, with an ever?increasing number of disease?causing genes being discovered. Most epilepsy?causing mutations are germ line and thus present from conception. These mutations are therefore well positioned to have a deleterious impact during early development. Here [researchers] review studies that investigate the role of genetic lesions within the early developmental window, specifically focusing on genetic generalized epilepsy (GGE). Literature on the potential pathogenic role of sub?mesoscopic structural changes in GGE is also reviewed.

Evidence from rodent models of genetic epilepsy support the idea that functional and structural changes can occur in early development, leading to altered seizure susceptibility into adulthood. Both animal and human studies suggest that sub?mesoscopic structural changes occur in GGE.

The existence of sub?mesoscopic structural changes prior to seizure onset may act as biomarkers of excitability in genetic epilepsies. [Researchers] also propose that presymptomatic treatment may be essential for limiting the long?term consequences of disease?causing mutations in genetic epilepsies.

Study: Effects of [Mutations in Genes] UGT2B7, SCN1A and CYP3A4 on the Therapeutic Response of Sodium Valproate Treatment in Children with Generalized Seizures

PURPOSE: This study aims to evaluate the associations between genetic polymorphisms and the effect of sodium valproate (VPA) therapy in children with generalized seizures.

METHODS: A total of 174 children with generalized seizures on VPA therapy were enrolled. Steady-state trough plasma concentrations of VPA were analyzed. Seventy-six single nucleotide polymorphisms involved in the absorption, metabolism, transport, and target receptor of VPA were identified, and their associations with the therapeutic effect (seizure reduction) were evaluated using logistic regression adjusted by various influence factors.

RESULTS: rs7668282 (UGT2B7, T?>?C, OR?=?2.67, 95% CI: 1.19 to 5.91, P?=?0.017) was more prevalent in drug-resistant patients than drug-responsive patients. rs2242480 (CYP3A4, C?>?T, OR?=?0.27, 95% CI: 0.095 to 0.79, P?=?0.017) and rs10188577 (SCN1A, T?>?C, OR?=?0.40, 95% CI: 0.17 to 0.94, P?=?0.035) were more prevalent in drug-responsive patients compared to drug-resistant patients.

CONCLUSION: In children with generalized seizures on VPA therapy, polymorphisms of UGT2B7, CYP3A4, and SCN1A genes were associated with seizure reduction. Larger studies are warranted to corroborate the results.