Sporadic & Familial Hemiplegic Migraine Have Genetic Link
The two disorders may be part of the same disease spectrum
TUESDAY, Dec. 4 (HealthDay News) -- Some individuals with sporadic hemiplegic migraine (SHM) -- a severe migraine subtype that involves transient hemiparesis -- carry gene mutations that are associated with familial hemiplegic migraine (FHM), suggesting that the two diseases may be part of a disease spectrum with similar pathogenesis, researchers report in an article published in the Dec. 4 issue of Neurology.
B. de Vries, of Leiden University Medical Centre in Leiden, the Netherlands, and colleagues screened 39 patients with SHM who did not have any associated neurologic features for three FHM gene mutations, involving a calcium channel (CACNA1A), a sodium-potassium pump (ATP1A2) and a sodium channel (SCN1A). The researchers then performed functional assays on all new sequence variants.
Seven of the 39 patients with SHM were identified as having sequence variants in one of the three FHM genes: one CACNA1A mutation, five ATP1A2 mutations and one SCN1A polymorphism. Six mutations induced functional changes in cellular assays and could be considered causal mutations. One patient's status was changed from SHM to FHM when a family member developed hemiplegic migraines.
"Because FHM mutations were also found in SHM and common types of migraine with or without aura, our findings reinforce the growing evidence that FHM, SHM, basilar-type migraine, and 'normal' migraine are part of a disease spectrum with at least some shared pathogenetic pathways," the authors conclude.