In contrast to those with high concussion tolerance, a mild head impact can cause devastating injury in people with familial hemiplegic migraine (FHM) type 1, an autosomal dominant form of migraine with aura caused by gain-of-function mutations in the calcium channel gene (CACNA1A or Cav2.1) [7, 8]. Here, CACNA1A is linked to familial hemiplegic migraine.