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Case Reports
. 2020 Aug;91(8):898-900.
doi: 10.1136/jnnp-2020-323173. Epub 2020 Jun 2.

Homozygous C-terminal loss-of-function NaV1.4 variant in a patient with congenital myasthenic syndrome

Andoni Echaniz-Laguna  1   2   3 , Valérie Biancalana  4   5 , Aleksandra Nadaj-Pakleza  6 , Emmanuel Fournier  7 , Emma Matthews  8 , Michael G Hanna  8 , Roope Männikkö  9
Affiliations
Case Reports

Homozygous C-terminal loss-of-function NaV1.4 variant in a patient with congenital myasthenic syndrome

Andoni Echaniz-Laguna et al. J Neurol Neurosurg Psychiatry. 2020 Aug.
No abstract available

Keywords: channels; myasthenia; neuromuscular.

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Conflict of interest statement

Competing interests: None declared.

Figures

Figure 1
Figure 1
Functional characterization of the P1650L variant. A. Sequence alignment of Nav family. Fully conserved proline is highlighted in grey. Fully conserved residues are indicated by *. B. Table of parameters for wild-type and P1650L channels. Number of cells is shown in parenthesis for each parameter. **: p<0.01. C. Representative traces of wild-type and P1650L activation in response to voltage steps ranging from -60 mV to + 10 mV. X-axis: 2 ms, y-axis: 20 pA/pF. D-J. Wild-type data is shown in open symbols, P1650L data in closed symbols. Solid lines show fit of Boltzmann (E-G) or exponential (H-I) equation to mean data. D. Current density is plotted against test voltage. E. Voltage dependence of activation. Peak conductance is plotted against test voltage. F-G. Voltage dependence of fast (F) and slow (G) inactivation. Current in response to test pulse is plotted against the pre-pulse voltage. H. Recovery from inactivation. Current in response to a second test pulse relative to current in response to first pulse is plotted against the duration at recovery voltage -80 mV. I. Onset of close state inactivation. Current in response to test pulse is plotted against duration of pre-pulse to -60 mV. J. Open state inactivation. Time constant of a fit of an exponential curve to inactivation following channel opening is plotted against the test voltage.
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