Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive weakness and muscular atrophy in the upper or lower limbs, ultimately leading to paralysis and death. Genetic studies have demonstrated that mutation in the gene encoding fused in sarcoma (FUS) is an uncommon cause of ALS. Here, we report a case of a 31-year-old Asian man with ALS with rare onset of dropped-head syndrome. Symptoms, including asymmetric proximal weakness of the upper limbs, hoarseness, dysphagia, and nocturnal dyspnea, emerged over a period of 5 months. After genetic testing, the patient was confirmed to harbor a novel pathogenic heterozygous mutation, c.1558C > T (p.R520C). We summarize the genotype-clinical phenotype relationships in 42 Asian patients with ALS-FUS.
Keywords: Amyotrophic lateral sclerosis; fused in sarcoma; genotype-phenotype correlation.