Mutation analysis of KIF5A in Chinese amyotrophic lateral sclerosis patients

Amyotrophic lateral sclerosis (ALS) is an age-related fatal neurodegenerative orphan disorder that is characterized by progressive injury of both the upper and lower motor neurons. Recently, loss-of-function mutations predominately disrupting the C-terminal amino acid sequence of KIF5A via aberrant exon 27 splicing have been reported in European ALS cohorts. However, the contributions of KIF5A mutations in Asian patients with ALS remain unclear. KIF5A sequences, including exons 26 and 27, were analyzed in a large Chinese ALS cohort comprising 33 unrelated familial ALS probands, 645 sporadic ALS (SALS) patients, 15 ALS patients presenting with concomitant frontotemporal dementia, 400 in-house controls, and 12,951 East Asian individuals from the Exome Aggregation Consortium and Genome Aggregation Database databases. As a result, the previously reported canonical splicing site mutation c.2993-1G>A was found in 1 SALS patient, while no mutations were detected in familial ALS case or ALS patients presenting with concomitant frontotemporal dementia. The frequency of KIF5A mutations accounts for 0.16% (1/645) of Chinese SALS patients, implying that it is an uncommon genetic determinant of ALS in Chinese patients.