Objective: To characterize phenotypes of a novel CACNA1A mutation causing familial hemiplegic migraine type 1.
Background: Familial hemiplegic migraine is a rare monogenic form of migraine associated with attacks of fully reversible unilateral motor weakness. We now report a novel CACNA1A gene mutation associated with fully reversible bilateral motor weakness (diplegia).
Methods: The proband underwent genotyping which identified a novel CACNA1A missense mutation (c.622 [isoform 1] G > A [p.Gly208Arg]). To characterize phenotypes associated with this novel mutation, the proband and 8 of her similarly affected family members underwent a semi-structured interview.
Results: All 9 subjects who were interviewed met ICHD-3 phenotypic diagnostic criteria for FHM, including reporting attacks with reversible unilateral motor weakness. Additionally, 7 of 9 subjects reported attacks including reversible motor weakness affecting both sides of the body simultaneously.
Conclusions: We describe a novel CACNA1A mutation associated with migraine attacks including reversible diplegia.
Keywords: CACNA1A mutation; FHM1; familial hemiplegic migraine.
© 2020 American Headache Society.