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 migrating focal seizures, and intellectual disability or autism without epilepsy. To assess the response to antiepileptic therapy, we retrospectively reviewed the treatment regimen and the course of the epilepsy in 66 patients for which well-documented medical information was available. We find that the use of sodium channel blockers was often associated with clinically relevant seizure reduction or seizure freedom in children with early infantile epilepsies (<3 months), whereas other antiepileptic drugs were less effective. In contrast, sodium channel blockers were rarely effective in epilepsies with later onset (≥3 months) and sometimes induced seizure worsening. Regarding the genetic findings, truncating mutations were exclusively seen in patients with late onset epilepsies and lack of response to sodium channel blockers. Functional characterization of four selected missense mutations using whole cell patch-clamping in tsA201 cells-together with data from the literature-suggest that mutations associated with early infantile epilepsy result in increased sodium channel activity with gain-of-function, characterized by slowing of fast inactivation, acceleration of its recovery or increased persistent sodium current. Further, a good response to sodium channel blockers clinically was found to be associated with a relatively small gain-of-function. In contrast, mutations in patients with late-onset forms and an insufficient response to sodium channel blockers were associated with loss-of-function effects, including a depolarizing shift of voltage-dependent activation or a hyperpolarizing shift of channel availability (steady-state inactivation). Our clinical and experimental data suggest a correlation between age at disease onset, response to sodium channel blockers and the functional properties of mutations in children with SCN2A-related epilepsy.
Ortho-lithiated styrenes or ortho-lithiated benzaldehyde dimethyl acetals were added to 2,2-dimethoxypent-4-enals 7. The resulting alcohols were carried on to the aromatic dienones 10. These were ring-closed by olefin metathesis. Hydrolysis of the dimethyl ketal moiety and enolization provided the 3,4-benzotropolones 5. Overall, this access comprises 4-6 steps and totaled a 22-81% yield.
Type-18 or -23 benzocycloheptadienones are readily prepared by ring-closing olefin metatheses. Adding Br to 23 and eliminating HBr gave the bromoolefin 28 using DBU or its isomer iso-28 using DABCO, both with near-perfect regiocontrol. Both 28 and iso-28 underwent Sonogashira, Suzuki, Negishi, and Heck couplings as well as Pd-catalyzed alkoxycarbonylations. Hydrolysis of the resulting α-ketoketals and enolization of the liberated α-diketones delivered a portfolio of hitherto unknown 3,4-benzotropolones. The 8-ethoxycarbonylated dimethyl-3,4-benzotropolone 50 obtained by this route was dimethylated to give goupiolone A (52). This synthesis encompasses 9 steps from 22, that is, half as many as the only previous synthesis (19 steps). A variant of our route afforded the 1,8-dibromide 54. Coupling with excess phenylboronic acid and ketal hydrolysis provided the diphenylated benzotropolone 56 and suggests a strategy, by which the natural bispulvinone aurantricholone (7) might be reached.
Summary:Purpose: Valproic acid (VPA) is an antiepileptic drug (AED) commonly used for generalized and focal epilepsies. We provide an update on hepatotoxic side effects in Germany between 1994 and 2003.Methods: We mailed a questionnaire to all members of the German Section of the International League Against Epilepsy, asking for VPA-induced side effects, especially severe side effects such as hepatopathy.
Comprehensive comparisons of 1H and 13C NMR chemical shift values in the furanone cores a, b, and c provide plausible support for a reassessment of the furanone nuclei of the title compounds from b to c. Total syntheses via enantiomerically pure lactic esters were based on the Seebach–Fráter “self‐reproduction of stereocenters” methodology. Attachment of the hexadienyl side‐chain in a trans,trans‐selective manner was achieved by addition of the Seebach–Fráter enolate to trans‐hex‐4‐en‐1‐al rather than to trans‐hex‐3‐en‐1‐al. The type‐c furanone cores of the synthetic materials were reached by single or double acylation of a model γ‐hydroxy‐β‐oxo ester (compound 50) and its hexadiene‐containing counterpart 29. Our syntheses confirmed the novel connectivities in six compounds. In addition, they required revision of the configuration of a quaternary carbon atom in five cases. Moreover, they allowed elucidation of the configurations of four previously unassigned stereocenters. Hindsight analyses of why the furanone cores of the title compounds had been misinterpreted as a and/or b instead of c are given. Why the stereocenters in the heterocycles had been incorrectly configured, on the bases (a) of relay studies in the 1960s, and (b) of a 1984 total synthesis of gregatin B, is also discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.