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Glut1 deficiency syndrome (Glut1DS) is a brain energy failure syndrome caused by impaired glucose transport across brain tissue barriers. Glucose diffusion across tissue barriers is facilitated by a family of proteins including glucose... more
Glut1 deficiency syndrome (Glut1DS) is a brain energy failure syndrome caused by impaired glucose transport across brain tissue barriers. Glucose diffusion across tissue barriers is facilitated by a family of proteins including glucose transporter type 1 (Glut1). Patients are treated effectively with ketogenic diet therapies (KDT) that provide a supplemental fuel, namely ketone bodies, for brain energy metabolism. The increasing complexity of Glut1DS, since its original description in 1991, now demands an international consensus statement regarding diagnosis and treatment. International experts (n = 23) developed a consensus statement utilizing their collective professional experience, responses to a standardized questionnaire, and serial discussions of wide‐ranging issues related to Glut1DS. Key clinical features signaling the onset of Glut1DS are eye‐head movement abnormalities, seizures, neurodevelopmental impairment, deceleration of head growth, and movement disorders. Diagnosis...
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Glut1 Deficiency (Glut1D) is caused by impaired glucose transport into brain. The resulting epileptic encephalopathy and movement disorders can be treated effectively by high-fat carbohydrate-restricted ketogenic diet therapies (KDT)... more
Glut1 Deficiency (Glut1D) is caused by impaired glucose transport into brain. The resulting epileptic encephalopathy and movement disorders can be treated effectively by high-fat carbohydrate-restricted ketogenic diet therapies (KDT) mimicking fasting and providing ketones as an alternative cerebral fuel. Recently 6-24 months follow-ups of epileptic patients reported elevated blood lipids and intima thickening of the carotid artery raising concerns about potential cardiovascular risks by KDT. To clarify potential cardiovascular risks we performed a prospective 10 year follow up of 10 Glut1D patients. Between August 2001 and January 2016 we enrolled Glut1D patients on KDT at two hospitals in Germany in this prospective, multicenter case series. The minimal follow up was 10 years. Standard deviation scores (SDS) of body mass index (BMI), total cholesterol (TC), HDL-/LDL cholesterol, and triglycerides (TG) before initiation of KDT were compared with respective values at 6 months, 2, 5 ...
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Multiple sulfatase deficiency (MSD) is an ultra-rare neurodegenerative disorder that results in defective sulfatase post-translational modification. Sulfatases in the body are activated by a unique protein, formylglycine-generating enzyme... more
Multiple sulfatase deficiency (MSD) is an ultra-rare neurodegenerative disorder that results in defective sulfatase post-translational modification. Sulfatases in the body are activated by a unique protein, formylglycine-generating enzyme (FGE) that is encoded by SUMF1. When FGE is absent or insufficient, all 17 known human sulfatases are affected, including the enzymes associated with metachromatic leukodystrophy (MLD), several mucopolysaccharidoses (MPS II, IIIA, IIID, IVA, VI), chondrodysplasia punctata, and X-linked ichthyosis. As such, individuals demonstrate a complex and severe clinical phenotype that has not been fully characterized to date. In this report, we describe two individuals with distinct clinical presentations of MSD. Also, we detail a comprehensive systems-based approach to the management of individuals with MSD, from the initial diagnostic evaluation to unique multisystem issues and potential management options. As there have been no natural history studies to d...
Research Interests: Medicine, Prevention, Consensus, Therapy, Care, and 3 moreClinical Sciences, Outcomes, and Leukodystrophy
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Glucose transporter type 1 deficiency syndrome (GLUT1DS) is a neurometabolic disorder with a complex phenotypic spectrum but simple biomarkers in cerebrospinal fluid. The disorder is caused by impaired glucose transport into the brain... more
Glucose transporter type 1 deficiency syndrome (GLUT1DS) is a neurometabolic disorder with a complex phenotypic spectrum but simple biomarkers in cerebrospinal fluid. The disorder is caused by impaired glucose transport into the brain resulting from variants in SCL2A1. In 10% of GLUT1DS patients, a genetic diagnosis can not be made. Using whole-genome sequencing, we identified a de novo 5'-UTR variant in SLC2A1, generating a novel translation initiation codon, severely compromising SLC2A1 function. This finding expands our understanding of the disease mechanisms underlying GLUT1DS and encourages further in-depth analysis of SLC2A1 non-coding regions in patients without variants in the coding region.
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Mutations in SCN2A, a gene encoding the voltage-gated sodium channel Nav1.2, have been associated with a spectrum of epilepsies and neurodevelopmental disorders. Here, we report the phenotypes of 71 patients and review 130 previously... more
Mutations in SCN2A, a gene encoding the voltage-gated sodium channel Nav1.2, have been associated with a spectrum of epilepsies and neurodevelopmental disorders. Here, we report the phenotypes of 71 patients and review 130 previously reported patients. We found that (i) encephalopathies with infantile/childhood onset epilepsies (≥3 months of age) occur almost as often as those with an early infantile onset (<3 months), and are thus more frequent than previously reported; (ii) distinct phenotypes can be seen within the late onset group, including myoclonic-atonic epilepsy (two patients), Lennox-Gastaut not emerging from West syndrome (two patients), and focal epilepsies with an electrical status epilepticus during slow sleep-like EEG pattern (six patients); and (iii) West syndrome constitutes a common phenotype with a major recurring mutation (p.Arg853Gln: two new and four previously reported children). Other known phenotypes include Ohtahara syndrome, epilepsy of infancy with mig...
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Glut1 Deficiency (Glut1D, OMIM #606777) is caused by impaired glucose transport into the brain. The resulting cerebral “energy crisis” causes intractable seizures, developmental delay, and a complex movement disorder. The diagnosis is... more
Glut1 Deficiency (Glut1D, OMIM #606777) is caused by impaired glucose transport into the brain. The resulting cerebral “energy crisis” causes intractable seizures, developmental delay, and a complex movement disorder. The diagnosis is based on clinical features, low CSF glucose and/or mutations in the SLC2A1 gene. Paroxysmal exertion-induced dystonia (PED) and hereditary cryohydrocytosis have been described as allelic variants. Adults are increasingly being recognized through family pedigrees. The condition is effectively treatable by mimicking the metabolic state of fasting. High-fat carbohydrate-restricted ketogenic diets generate ketones that serve as an alternative fuel for the brain. In adults with Glut1D, novel modified ketogenic diets can be used, allowing more carbohydrates and greater palatability and compliance.
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High-fat ketogenic diets are the only treatment available for Glut1 deficiency (Glut1D). Here, we describe an 8-year-old girl with classical Glut1D responsive to a 3:1 ketogenic diet and ethosuximide. After 3 years on the diet a gradual... more
High-fat ketogenic diets are the only treatment available for Glut1 deficiency (Glut1D). Here, we describe an 8-year-old girl with classical Glut1D responsive to a 3:1 ketogenic diet and ethosuximide. After 3 years on the diet a gradual increase of blood lipids was followed by rapid, severe asymptomatic hypertriglyceridemia (1,910 mg/dL). Serum lipid apheresis was required to determine liver, renal, and pancreatic function. A combination of medium chain triglyceride-oil and a reduction of the ketogenic diet to 1:1 ratio normalized triglyceride levels within days but triggered severe myoclonic seizures requiring comedication with sultiam. Severe hypertriglyceridemia in children with Glut1D on ketogenic diets may be underdiagnosed and harmful. In contrast to congenital hypertriglyceridemias, children with Glut1D may be treated effectively by dietary adjustments alone.
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To give a comprehensive overview of the phenotypic and genetic spectrum of STXBP1 encephalopathy (STXBP1-E) by systematically reviewing newly diagnosed and previously reported patients. We recruited newly diagnosed patients with STXBP1... more
To give a comprehensive overview of the phenotypic and genetic spectrum of STXBP1 encephalopathy (STXBP1-E) by systematically reviewing newly diagnosed and previously reported patients. We recruited newly diagnosed patients with STXBP1 mutations through an international network of clinicians and geneticists. Furthermore, we performed a systematic literature search to review the phenotypes of all previously reported patients. We describe the phenotypic features of 147 patients with STXBP1-E including 45 previously unreported patients with 33 novel STXBP1 mutations. All patients have intellectual disability (ID), which is mostly severe to profound (88%). Ninety-five percent of patients have epilepsy. While one-third of patients presented with Ohtahara syndrome (21%) or West syndrome (9.5%), the majority has a nonsyndromic early-onset epilepsy and encephalopathy (53%) with epileptic spasms or tonic seizures as main seizure type. We found no correlation between severity of seizures and ...
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Research Interests: Medicine and Gynecology
Glucide metabolism comprises pathways for transport, intermediate metabolism, utilization, and storage of carbohydrates. Defects affect multiple organs and present as systemic diseases. Neurological symptoms result from hypoglycemia,... more
Glucide metabolism comprises pathways for transport, intermediate metabolism, utilization, and storage of carbohydrates. Defects affect multiple organs and present as systemic diseases. Neurological symptoms result from hypoglycemia, lactic acidosis, or inadequate storage of complex glucide molecules in neurological tissues. In glycogen storage disorders hypoglycemia indicates hepatic involvement, weakness and muscle cramps muscle involvement. Hypoglycemia is also the leading neurological symptom in disorders of gluconeogenesis. Disorders of galactose and fructose metabolism are rare, detectable by neonatal screening, and manifest following dietary intake of these sugars. Rare defects within the pentose metabolism constitute a new area of inborn metabolic disorders and may present with neurological symptoms. Treatment of these disorders involves the avoidance of fasting, dietary treatment eliminating specific carbohydrates, and enzyme replacement therapy in individual glycogen stora...
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Carbohydrates are one of the most important sources of energy in the human organism. Within the body, glucose is the most abundant monosaccharide which can be stored as glycogen, a branched polymer, in liver and muscle. Inborn errors of... more
Carbohydrates are one of the most important sources of energy in the human organism. Within the body, glucose is the most abundant monosaccharide which can be stored as glycogen, a branched polymer, in liver and muscle. Inborn errors of metabolism may affect the uptake, distribution and reabsorption of monosaccharides in different organs, a process which is meticulously regulated by a system of transporter proteins. Congenital disorders may impair the conversion of other monosaccharides (fructose, galactose) into glucose. They can further affect glycogen formation, glycogen breakdown (glycogenolysis), glucose metabolism to acetyl-CoA (glycolysis) and de novo synthesis of glucose from glucoplastic amino acids or from lactate (gluconeogenesis).
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Research Interests: Genetics, Immune response, Biology, Medicine, Biological Sciences, and 15 moreDNA, Humans, Mutation, Female, Male, Gene, Enzyme, Amino Acid Sequence, Base Sequence, Protein Quaternary Structure, Autosomal Recessive, Molecular Sequence Data, ribonuclease, Medical and Health Sciences, and Protein subunits
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Glucose transporter 1 (GLUT1) deficiency syndrome (DS) results from impaired glucose transport into brain. We describe the case of an 8-year-old girl with early-onset myoclonic epilepsy unresponsive to eight anticonvulsants. Oral steroid... more
Glucose transporter 1 (GLUT1) deficiency syndrome (DS) results from impaired glucose transport into brain. We describe the case of an 8-year-old girl with early-onset myoclonic epilepsy unresponsive to eight anticonvulsants. Oral steroid treatment achieved dramatic seizure control at the expense of Cushing syndrome and progressive fatty liver disease. Steroid withdrawal resulted in severe seizure exacerbation but was eventually enforced for lumbar puncture. GLUT1DS was diagnosed by hypoglycorrhachia and a heterozygous SLC2A1 mutation (Arg400His). A ketogenic diet resulted in effective seizure control. Steroids in GLUT1DS are unusual and unreported. Here a remarkable immediate and effective seizure control and a dose-independent unsuccessful steroid withdrawal indicated a potential GLUT1 sensitivity to steroids. We review the literature on GLUT1/steroid interactions and propose that unusual steroid sensitivity in intractable childhood epilepsy might be indicative for GLUT1DS.
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The classical ketogenic diet has been used for refractory childhood epilepsy for decades. It is also the treatment of choice for disorders of brain energy metabolism, such as Glut1 deficiency syndrome. Novel ketogenic diets such as the... more
The classical ketogenic diet has been used for refractory childhood epilepsy for decades. It is also the treatment of choice for disorders of brain energy metabolism, such as Glut1 deficiency syndrome. Novel ketogenic diets such as the modified Atkins diet and the low glycemic index treatment have significantly improved the therapeutic options for dietary treatment. Benefits of these novel diets are increased palatability, practicability, and thus compliance—at the expense of lower ketosis. As high ketones appear essential to meet the brain energy deficit caused by Glut1 deficiency syndrome, the use of novel ketogenic diets in this entity may be limited. This article discusses the current data on novel ketogenic diets and the implications on the use of these diets in regard to Glut1 deficiency syndrome.
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SummaryThe ketogenic diet (KD) is an established, effective nonpharmacologic treatment for intractable childhood epilepsy. The KD is provided differently throughout the world, with occasionally significant variations in its... more
SummaryThe ketogenic diet (KD) is an established, effective nonpharmacologic treatment for intractable childhood epilepsy. The KD is provided differently throughout the world, with occasionally significant variations in its administration. There exists a need for more standardized protocols and management recommendations for clinical and research use. In December 2006, The Charlie Foundation commissioned a panel comprised of 26 pediatric epileptologists and dietitians from nine countries with particular expertise using the KD. This group was created in order to create a consensus statement regarding the clinical management of the KD. Subsequently endorsed by the Practice Committee of the Child Neurology Society, this resultant manuscript addresses issues such as patient selection, pre‐KD counseling and evaluation, specific dietary therapy selection, implementation, supplementation, follow‐up management, adverse event monitoring, and eventual KD discontinuation. This paper highlights...
Research Interests: Neurology, Evidence Based Medicine, Epilepsy, Medicine, Humans, and 14 moreKetosis, Child, Drug Resistance, Dietary Supplements, Epilepsia, Clinical Sciences, Patient Care Team, Adverse Event, Neurosciences, Ketogenic diet, Combined Modality Therapy, Adverse effect, discontinuation, and Medical and Health Sciences
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The ketogenic diet is a rational treatment for pyruvate dehydrogenase complex deficiency (McKusick 312170) and GLUT1 deficiency syndrome (McKusick 138140). An increasing number of patients are diagnosed in early infancy, but few data are... more
The ketogenic diet is a rational treatment for pyruvate dehydrogenase complex deficiency (McKusick 312170) and GLUT1 deficiency syndrome (McKusick 138140). An increasing number of patients are diagnosed in early infancy, but few data are available on the introduction of a ketogenic diet in this age group. GLUT1 deficiency syndrome was suspected in four infants presenting with seizures and unexplained hypoglycorrhachia. A ketogenic diet was introduced at 6–28 weeks of age. Ketosis was initiated by fasting, monitored by bedside blood glucose and 3‐hydroxybutyrate determinations, and was maintained successfully using supplemented carbohydrate‐free infant formula and emulgated triglycerides. All patients developed ketosis within 24 h. 3‐Hydroxybutyrate concentrations available at the bedside correlated inversely with the base excess. At glucose levels ≤40 mg/dl patients remained asymptomatic in the presence of ketones. The ketogenic formula was tolerated well, parental compliance was go...