This website provides information on patients with familial/sporadic hemiplegic migraine type 2 (OMIM #602481), including clinical data, molecular data, management and research options.

Familial/Sporadic hemiplegic migraine type 2 (FHM2/SHM2) is caused by mutations in the ATP1A2 gene. FHM2/SHM2 is a severe subtype of migraine with aura. It is characterised by migrainous headaches accompanied by aura symptoms, which include transient motor weakness. The motor weakness is typical for FHM2/SHM2 and the severity may vary from mild paresis to hemiplegia. Additional clinical features can occur, such as epilepsy, prolonged hemiplegia, confusion, permanent mental retardation, impaired consciousness and coma. Hemiplegic migraine type 2 is subdivided in familial hemiplegic migraine type 2 (FHM2) and sporadic hemiplegic migraine type 2 (SHM2). Distinction can be made on the basis of having respectively a positive or negative family history for hemiplegic migraine. In rare cases mutations in ATP1A2 can also cause alternating hemiplegia of childhood 1 (AHC1, OMIM #104290). There is great overlap in the phenotypic spectrum between FHM2/SHM2 and AHC1. AHC1 is a neurodevelopmental disorder characterized by repeated episodes of hemiplegia and other paroxysmal and non-paroxysmal features leading to progressive cognitive and neurological decline, the age of onset is typically before 18 months of age.

Apart from ATP1A2 there are two other genes that can cause hemiplegic migraine. However, not all individuals with the clinical characteristics of hemiplegic migraine have a mutation in one of these genes. Moreover, not all individuals with a mutation in these genes have disease features.

This website was created to share and collect information about clinic, management and research projects to gather more knowledge and provide better treatment of patients with mutations in the ATP1A2 gene.

Arn M.J.M. van den Maagdenberg, PhD, Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands, A.M.J.M.van_den_Maagdenberg@lumc.nl

Mariëtte J.V. Hoffer, PhD, Departments of Clinical Genetics, Leiden University Medical Centre, Leiden, The Netherlands, M.J.V.Hoffer@lumc.nl

Aster V.E. Harder, MD, Departments of Neurology, Leiden University Medical Centre, Leiden, The Netherlands, A.V.E.Harder@lumc.nl