Loss of synaptic Zn2+ transporter function increases risk of febrile seizures.
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Hildebrand MS, Phillips AM, Mullen SA, Adlard PA, Hardies K, Damiano JA, Wimmer V, Bellows ST, McMahon JM, Burgess R, Hendrickx R, Weckhuysen S, Suls A, De Jonghe P, Scheffer IE, Petrou S, Berkovic SF, Reid CA
Loss of synaptic Zn2+ transporter function increases risk of febrile seizures.
Sci Rep. 2015 Dec 9;5:17816. doi: 10.1038/srep17816.
- PubMed ID
- 26647834 [ View in PubMed]
- Abstract
Febrile seizures (FS) are the most common seizure syndrome and are potentially a prelude to more severe epilepsy. Although zinc (Zn(2+)) metabolism has previously been implicated in FS, whether or not variation in proteins essential for Zn(2+) homeostasis contributes to susceptibility is unknown. Synaptic Zn(2+) is co-released with glutamate and modulates neuronal excitability. SLC30A3 encodes the zinc transporter 3 (ZNT3), which is primarily responsible for moving Zn(2+) into synaptic vesicles. Here we sequenced SLC30A3 and discovered a rare variant (c.892C > T; p.R298C) enriched in FS populations but absent in population-matched controls. Functional analysis revealed a significant loss-of-function of the mutated protein resulting from a trafficking deficit. Furthermore, mice null for ZnT3 were more sensitive than wild-type to hyperthermia-induced seizures that model FS. Together our data suggest that reduced synaptic Zn(2+) increases the risk of FS and more broadly support the idea that impaired synaptic Zn(2+) homeostasis can contribute to neuronal hyperexcitability.