Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 50-year-old male presented with complaints of fatigue, confusion, and memory problems. Neurological evaluation revealed altered cognition, unsteady gait, ataxia, dysmetria, and weakness. MRI of the brain was initially unremarkable. Over several days, the patient experienced improvement of symptoms and a follow-up MRI revealed a small lesion in the splenium of the corpus callosum seen on diffusion weighted and T2 sequences. The patient was discovered to have elevated anti-voltage gated potassium channel serum autoantibodies. Follow-up MRI revealed resolution of the splenial lesion. The patient was treated with intravenous immune globulin, and improved back to his pre-treatment baseline. We believe this to be the first case of a reversible splenial lesion syndrome as a manifestation of the anti-voltage gated potassium channel autoantibody syndrome, and propose a pathophysiologic mechanism.
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PMID:Association of reversible splenial lesion syndrome (RESLES) with Anti-VGKC autoantibody syndrome: a case report. 2674 64

Episodic ataxia type 1 (EA1) is a human dominant neurological syndrome characterized by continuous myokymia, episodic attacks of ataxic gait and spastic contractions of skeletal muscles that can be triggered by emotional stress and fatigue. This rare disease is caused by missense mutations in the KCNA1 gene coding for the neuronal voltage gated potassium channel Kv1.1, which contributes to nerve cell excitability in the cerebellum, hippocampus, cortex and peripheral nervous system. We identified a novel KCNA1 mutation, E283K, in an Italian proband presenting with paroxysmal ataxia and myokymia aggravated by painful contractures and metabolic dysfunctions. The E283K mutation is located in the S3-S4 extracellular linker belonging to the voltage sensor domain of Kv channels. In order to test whether the E283K mutation affects Kv1.1 biophysical properties we transfected HEK293 cells with WT or mutant cDNAs alone or in a 1:1 combination, and recorded relative potassium currents in the whole-cell configuration of patch-clamp. Mutant E283K channels display voltage-dependent activation shifted by 10mV toward positive potentials and kinetics of activation slowed by ~2 fold compared to WT channels. Potassium currents resulting from heteromeric WT/E283K channels show voltage-dependent gating and kinetics of activation intermediate between WT and mutant homomeric channels. Based on homology modeling studies of the mutant E283K, we propose a molecular explanation for the reduced voltage sensitivity and slow channel opening. Overall, our results suggest that the replacement of a negatively charged residue with a positively charged lysine at position 283 in Kv1.1 causes a drop of potassium current that likely accounts for EA-1 symptoms in the heterozygous carrier.
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PMID:A novel KCNA1 mutation in a patient with paroxysmal ataxia, myokymia, painful contractures and metabolic dysfunctions. 2866 63