IllnessEpilepsies, metabolic; differentialdiagnosis

NGS +

[[Sanger]]

Neuro-metabolic epilepsies are inherited disorders with predominantly epileptic manifestations, or the epilepsy is part of a complex neurologic phenotype. Several of these disorders are treatable, but there are no specific clinical or electrographic features suggestive of metabolic epilepsies. Metabolic disorders can cause seizures in three different ways: Deficiency of substrates essential for neuro-cellular metabolism or membrane function, intracellular accumulation of neurotoxic substances, and alteration of intracellular osmolality in the brain. Thus, about half of the approximately 400 inborn errors of metabolism, i.e., manifold mutations in nearly 900 genes, may be associated with epilepsies. A search of the OMIM, PubMed and MEDLINE databases reveals that the majority of inborn errors of metabolism in epilepsy are transmitted in autosomal recessive manner (87%), whereas 6% are inherited in mitochondrial, 4% in X-linked and 3% in autosomal dominant manner. According to different study results, the DNA diagnostic yield can vary between 25-65% and more, so that nevertheless inconspicuous genetic findings do not mean a secure exclusion of the clinical suspected diagnoses.

References: https://www.ncbi.nlm.nih.gov/books/NBK1195/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6369901/

• Allelic: Anemia, sideroblastic, 3, pyridoxine-refractory (GLRX5)
• Allelic: Aphasia, primary progressive (GRN)
• Allelic: Behr syndrome (OPA1)
• Allelic: Charcot-Marie-Tooth disease, axonal, type 2EE (MPV17)
• Allelic: Deafness, AD 65 (TBC1D24)
• Allelic: Deafness, AR 86 (TBC1D24)
• Allelic: Dystonia 9 (SLC2A1)
• Allelic: Fanconi renotubular syndrome 1 (GATM)
• Allelic: Frontotemporal lobar degeneration with ubiquitin-positive inclusions (GRN)
• Allelic: Glaucoma, normal tension, susceptibility to (OPA1)
• Allelic: Leiomyomatosis + renal cell cancer (FH)
• Allelic: Macular dystrophy with central cone involvement (MFSD8)
• Allelic: Mitochondrial DNA depletion syndrome 2, myopathic type (TK2)
• Allelic: Optic atrophy 1 (OPA1)
• Allelic: Optic atrophy plus syndrome (OPA1)
• Allelic: Perrault syndrome 5 (TWNK)
• Allelic: Portal hypertension, noncirrhotic, 1 (DGUOK)
• Allelic: Progressive external ophthalmoplegia with mitochondrial DNA deletions, AR 4 (DGUOK)
• Allelic: Progressive external ophthalmoplegia, AD 1 (POLG)
• Allelic: Progressive external ophthalmoplegia, AR 1 (POLG)
• Allelic: Spastic paraplegia 74, AR (IBA57)
• Branched-chain ketoacid dehydrogenase kinase deficiency (BCKDK)
• Cerebral creatine deficiency syndrome 2 (GAMT)
• Cerebral creatine deficiency syndrome 3 (GATM)
• Ceroid lipofuscinosis, neuronal, 1 (PPT1)
• Ceroid lipofuscinosis, neuronal, 10 (CTSD)
• Ceroid lipofuscinosis, neuronal, 11 (GRN)
• Ceroid lipofuscinosis, neuronal, 13, Kufs type, AD (CTSF)
• Ceroid lipofuscinosis, neuronal, 2 (TPP1)
• Ceroid lipofuscinosis, neuronal, 3 (CLN3)
• Ceroid lipofuscinosis, neuronal, 4, Kufs type (DNAJC5)
• Ceroid lipofuscinosis, neuronal, 5 (CLN5)
• Ceroid lipofuscinosis, neuronal, 6A (CLN6)
• Ceroid lipofuscinosis, neuronal, 6B, Kufs type (CLN6)
• Ceroid lipofuscinosis, neuronal, 7 (MFSD8)
• Ceroid lipofuscinosis, neuronal, 8 (CLN8)
• Ceroid lipofuscinosis, neuronal, 8, Northern epilepsy variant (CLN8)
• Coenzyme Q10 deficiency, primary, 4 (COQ8A)
• Constitutional megaloblastic anemia with severe neurologic disease (DHFR)
• DOORS [Deafness, Onychodystrophy, Osteodystrophy, mental Retard.] syndrome (TBC1D24)
• Developmental + epileptic encephalopathy 16 (TBC1D24)
• Epilepsy, idiopathic generalized, susceptibility to, 12 (SLC2A1)
• Epilepsy, progressive myoclonic 3, with/-out intracellular inclusions (KCTD7)
• Epilepsy, pyridoxine-dependent (ALDH7A1)
• Epilepsy, rolandic, with proxysmal exercise-induce dystonia + writer's cramp (TBC1D24)
• Epilepsy-associated gene [Lit.] (SLC8A9)
• Fumarase deficiency (FH)
• GABA-transaminase deficiency (ABAT)
• GLUT1 deficiency syndrome 1, infantile onset, severe (SLC2A1)
• GLUT1 deficiency syndrome 2, childhood onset (SLC2A1)
• Glycine encephalopathy (GCSH)
• Glycine encephalopathy (GLDC)
• Glycine encephalopathy with normal serum glycine (SLC6A9)
• Hyperglycinemia, lactic acidosis + seizures (LIAS)
• Krabbe disease (GALC)
• L-2-hydroxyglutaric aciduria (L2HGDH)
• Megaloblastic anemia with severe neurologic disease (DHFR)
• Metabolic encephalomyopathic crises, recurrent, rhabdomyol., cardiac arrhythmias, neurodeg. (TANGO2)
• Metabolic encephalomyopathic crises, recurrent, rhabdomyolysis, cardiac arrhyth., neurodeg. (TANGO2)
• Methylmalonic acidemia + homocysteinemia, cblX type (HCFC1)
• Mitochondrial DNA depletion syndrome 1, MNGIE type (TYMP)
• Mitochondrial DNA depletion syndrome 12A, cardiomyopathic type, AD (SLC25A4
• Mitochondrial DNA depletion syndrome 12B, cardiomyopathic type, AR (SLC25A4)
• Mitochondrial DNA depletion syndrome 13, encephalomyopathic type (FBXL4)
• Mitochondrial DNA depletion syndrome 14, encephalocardiomyopathic type (OPA1)
• Mitochondrial DNA depletion syndrome 15, hepatocerebral type (TFAM)
• Mitochondrial DNA depletion syndrome 3, hepatocerebral type (DGUOK)
• Mitochondrial DNA depletion syndrome 4A, Alpers type (POLG)
• Mitochondrial DNA depletion syndrome 4B, MNGIE type (POLG)
• Mitochondrial DNA depletion syndrome 5, encephalomyopathic +/- methylmalonic aciduria (SULC2)
• Mitochondrial DNA depletion syndrome 6, hepatocerebral type (MPV17)
• Mitochondrial DNA depletion syndrome 7, hepatocerebral type (TWNK)
• Mitochondrial DNA depletion syndrome 8A, encephalomyopathic type with renal tubulopathy (RRM2B)
• Mitochondrial DNA depletion syndrome 8B, MNGIE type (RRM2B)
• Mitochondrial DNA depletion syndrome 9, encephalomyopathic type with methylmalonic aciduria (SUCLG1)
• Mitochondrial recessive ataxia syndrome (includes SANDO and SCAE] (POLG)
• Molybdenum cofactor deficiency A (MOCS1)
• Molybdenum cofactor deficiency B (MOCS2)
• Molybdenum cofactor deficiency C (GPHN)
• Multiple mitochondrial dysfunctions syndrome 1 (NFU1)
• Multiple mitochondrial dysfunctions syndrome 2 with hyperglycinemia (BOLA3)
• Multiple mitochondrial dysfunctions syndrome 3 (IBA57)
• Myoclonic epilepsy, infantile, familial (TBC1D24)
• Neurodegeneration due to cerebral folate transport deficiency (FOLR1)
• Progressive external ophthalmoplegia with mitochondrial DNA deletions, AD 2 (SLC25A4)
• Progressive external ophthalmoplegia with mitochondrial DNA deletions, AD 3 (TWNK)
• Progressive external ophthalmoplegia with mitochondrial DNA deletions, AD 5 (RRM2B)
• Progressive external ophthalmoplegia with mitochondrial DNA deletions, AR 2 (RNASEH1)
• Progressive external ophthalmoplegia with mitochondrial DNA deletions, AR 3 (TK2)
• Pyridoxamine 5'-phosphate oxidase deficiency (PNPO)
• Sengers syndrome (AGK)
• Spasticity, childhood-onset, with hyperglycinemia (GLRX5)
• Spinocerebellar ataxia, autosomal recessive 7 (TPP1)
• Stomatin-deficient cryohydrocytosis with neurologic defects (SLC2A1)
• Succinic semialdehyde dehydrogenase deficiency (ALDH5A1)
• Sulfite oxidase deficiency (SUOX)