The novel p.L1649Q mutation in the SCN1A epilepsy gene is associated with familial hemiplegic migraine: genetic and functional studies

✍ Scribed by Kaate R.J. Vanmolkot; Elena Babini; Boukje de Vries; Anine H. Stam; Tobias Freilinger; Gisela M. Terwindt; Lisa Norris; Joost Haan; Rune R. Frants; Nabih M. Ramadan; Michel D. Ferrari; Michael Pusch; Arn M.J.M. van den Maagdenberg; Martin Dichgans

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 492 KB
• Volume: 28
• Category: Article
• ISSN: 1059-7794
• DOI: 10.1002/humu.9486

✦ Synopsis

Familial hemiplegic migraine (FHM) is a severe subtype of migraine with hemiparesis during attacks. We scanned 10 families with FHM without mutations in the CACNA1A (FHM1) and ATP1A2 (FHM2) genes. We identified the novel p.L1649Q mutation (c.4946T>A) in Na(v)1.1 sodium channel gene SCN1A (FHM3) in a North American kindred with FHM without associated ataxia or epilepsy. Functional analysis of the mutation, introduced in the highly homologous human SCN5A, revealed markedly slowed inactivation and a two-fold faster recovery from fast inactivation predicting enhanced neuronal excitation. Our findings establish the role of neuronal Na(v)1.1 sodium channels in FHM and reinforce the involvement of ion channel dysfunction in the pathogenesis of this episodic brain disorder.