De novo FUS P525L mutation in Juvenile amyotrophic lateral sclerosis with dysphonia and diplopia.

Juvenile amyotrophic lateral sclerosis (jALS) is characterized by progressive upper and lower motor neuron degeneration leading to facial muscle spasticity, spastic dysarthria, and spastic gait with an early onset (before 25 years old). Unlike adult-onset amyotrophic lateral sclerosis (ALS), patients with jALS tend to have slower progression of motor neuron disease and prolonged survival to a normal life expectancy. Mutations in FUS gene have been reported in jALS,(1) including p.P525L mutation that has been consistently associated with early onset and aggressive presentation.(2) Here, we report a patient carrying p.P525L FUS mutation and experiencing an aggressive course of ALS presenting with dysphonia and diplopia.