|Number||Exon/Intron||Nucleotide change||Protein change||Location||Mutation type||Consequences||Phenotype||Inheritance||Reference|
|253||6||c.787C>G||p.Leu263Val||DIS5||Missense||N→N (32); GOF||FHM+EP||2Familial,P=5/5||Barros J.2014|
|Familial(Paternal, FHM+EP),P=5/5||Castro MJ.2009|
|HM + Ep||NA||Kahlig KM.2008|
|Number||Nucleotide change||Protein change||Location||Phenotype||Functional defect type||Details of the major biophysical abnormalities.||Reference|
|6||c.787C>G||p.Leu263Val(L263V)||DIS5||FHM+EP||GOF||Exhibited gain-of function features, including delayed entry into, as well as accelerated recovery from, fast inactivation; depolarizing shifts in the steady-state voltage dependence of fast and slow inactivation; increased persistent current; and delayed entry into slow inactivation.||Kahlig KM.2008|
|Number||Nucleotide change||Protein change||Mutation type||Proband's phenotype||1st transmitter's phenotype||Mosaic||Affected generations||Penetrance||Reference|
|[c.787C>G] Clinical description|
The Portuguese FHM family spans three generations. Six patients suffered from typical hemiplegic migraine attacks, with an age of onset varying from 10 to 18 years and an attack frequency of less than one to three per year. None of the patients reported (inter)ictal cerebellar abnormalities. Generalized tonic-clonic seizures (and in one case additional complex partial seizures) were co-segregating with hemiplegic migraine in three family members (i.e. II:2, II:5 and III:4), and probably in one deceased person (I:1) [seizures similar to those of the other family members were reported by his wife (I:2)]. Onset of seizures was between 4 and 8 years. Interictal EEG recording was unremarkable in patients II:2, II:5 and III:4. Structural lesions in these patients were excluded on the basis of computed tomography (i.e. II:2 and II:5) or magnetic resonance imaging (i.e. III:4) investigations (data not shown). Febrile convulsions were not reported in any of the family members. Epileptic seizures occurred independently from FHM attacks, and the age at onset was generally somewhat later than for the FHM attacks. Treatment with a low daily dose (400 mg/day) of carbamazepine in patients II:2 and II:5, who had a body weight of < 60 kg, was successful with respect to both epileptic and hemiplegic attacks as patients remained attack free. Patient III:4 occasionally had epileptic attacks when treated with a daily dose of 600 mg of carbamazepine, but he did not tolerate a higher dose. Psychomotor development of all individuals was normal(Castro MJ, et al. Cephalalgia. 2009 Mar; 29(3):308-13. ).
Copyright ©2014 Institute of Neuroscience and The Second Affiliated Hospital of Guangzhou Medical University
Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China
Collaborative Innovation Center for Neurogenetics and Channelopathies, Guangzhou 510260, China.