Clinical spectrum in three families with familial hemiplegic migraine type 2 including a novel mutation in the ATP1A2 gene

Introduction Familial hemiplegic migraine (FHM) is a rare subtype of migraine with transient hemiplegic aura. Patients and methods We describe three unrelated families with familial hemiplegic migraine type II (FHM2). Retrospectively, information on 47 family members could be obtained, 15 by personal examination and 32 by indirect anamnesis from relatives. Genetic analyses were performed in 13 patients. Results One family had a novel missense mutation in the ATP1A2 gene (c.659C>T, p.Ser220Leu) that segregated with the phenotype in three generations. Two further unrelated families with different ethnic backgrounds (one from Germany and one from Russia) had a missense mutation that has not been described as yet in FHM, but occurred in only a single patient with sporadic hemiplegic migraine (c.2723G>A, p.Arg908Gln). Clinically the patients had severe attacks lasting up to several weeks as well as epileptic seizures. Three patients with a proven mutation in the ATP1A2 gene clinically presented without hemiparesis. Furthermore, there was a possible relation of FHM2 to mental retardation in another two patients. Conclusion Clinical symptoms may last for several weeks in some patients. Patients with FHM2 may also present without hemiplegia. Therefore, the full family history has to be taken into account to establish the diagnosis of FHM.