Familial/Sporadic hemiplegic migraine type 2 (FHM2/SFHM2) is a subtype of migraine with aura, in which motor weakness is part of the aura. Additional clinical features can occur, such as epilepsy, prolonged hemiplegia, confusion, permanent mental retardation, impaired consciousness and coma. Also, attacks of a common non-hemiplegic migraine can occur.
Apart from ATP1A2 there are two other genes that can cause hemiplegic migraine. Patients with a mutation in one of these three genes often have a more severe phenotype, with extensive motor weakness and brainstem features, confusion and brain oedema compared to those with hemiplegic migraine without a mutation.
ATP1A2