We describe a sporadic amyotrophic lateral sclerosis (ALS) patient who presented rapid progress of muscle weakness and died of respiratory failure one and a half years after onset. Genetic analysis revealed a novel ALS-causing gene NEK1 nonsense mutation p.K1210* and a known pathogenic frontotemporal lobar degeneration (FTD)-causing gene GRN mutation p.C139R. It is rare for ALS patients to carry two different pathogenic mutations simultaneously. The individual only had typically motor neuron dysfunction without any related cognitive symptoms. GRN p.C139R mutation is linked to various clinical phenotypes that include FTD and Alzheimer's disease (AD). The case carrying two different gene mutations expands our understanding of ALS genetics.
Keywords: ALS; Chinese; GRN; NEK1; mutation.