Introduction

Amyotrophic lateral sclerosis (ALS) is a devastating motor neuron disorder with an unclear aetiology that overlaps with frontotemporal dementia (FTD). ALS is classified as either familial or sporadic, and both of these have genetic components. Knowledge of the genetic architecture of ALS has been facilitated by evolving gene-sequencing technologies. A significant excess burden of rare damaging TUBA4A variants was recently demonstrated in ALS cases via an exome scan in a case−control burden analysis.1 Several follow-up TUBA4A gene screenings were subsequently performed in ALS and FTD cohorts of Italian, Belgian and Spanish origin.2–4 However, the pathogenicity of several TUBA4A non-synonymous mutations is difficult to establish in the absence of cosegregation data, partly because ALS pedigrees are small and difficult to collect due to the late onset nature of the disorder. Here, we performed a thorough genetic analysis to determine the prevalence of TUBA4A variants in a hospital-based ALS cohort of Han Chinese origin.