Survival analysis of clinical and genetic factors in an amyotrophic lateral sclerosis cohort from China

Objectives To investigate the clinical and genetic factors influencing the survival of amyotrophic lateral sclerosis (ALS) patients in China. Methods Patients were enrolled in the study between December 2013 and December 2018. Clinical variables were recorded upon patient diagnosis. Causative genes related to ALS were screened by whole-exome sequencing and validated by Sanger sequencing. Each patient was followed up every 3-6 months until the endpoint (death or tracheotomy) or the last connection time on 31 December 2020. Propensity score matching analysis was performed to match the genetic and non-genetic ALS patients. The Kaplan-Meier method and multivariable Cox regression were performed for survival analysis. Results A total of 337 patients, including 32 with genetic ALS and 305 with non-genetic ALS, were enrolled in the study. Before matching, in univariate analysis, age of onset (P < 0.001), site of onset (P = 0.036), diagnostic delay (P < 0.001), ALSFRS-R score at diagnosis (P < 0.001), Delta ALSFRS-R (P < 0.001), and causative mutations (P = 0.020) were significant prognostic factors. These factors remained statistically significant after multivariate analysis. After matching, in the multivariate analysis, age of onset (P = 0.003), site of onset (P = 0.014), diagnostic delay (P = 0.007), ALSFRS-R score at diagnosis (P = 0.010), Delta ALSFRS-R (P = 0.007), and causative mutations (P = 0.003) were found to be significant prognostic factors. Conclusion Both clinical factors and genetic factors influenced survival in our ALS cohort. Clarifying of the underlying mechanisms is crucial for the development of future therapies.