Genetic abnormalities previously established to be associated with familial or sporadic ALS, dementia, familial Parkinson disease and parkinsonism, were sought in the cases in Kii, but none were identified.28, 42 Hermosura et al43 discovered a nuclear mutation in the calcium/magnesium membrane ion channel transient receptor potential melastatin 7 (TRPM7) gene in a subset of patients with ALS/PDC in Guam. Here, TRPM7 is linked to amyotrophic lateral sclerosis.