•Distribution of FUS in controls and ALS samples is limited to the nucleus.•Oxidative stress induces the amassment of cytoplasmic FUS in stress granules, thus mimicking pathological characteristics recognized in mutant FUS in ALS patient.•Cytoplasmic aggregation of FUS was observed in G504Wfs mutant carrier sample in contrast to the control and ALS samples.•In G504Wfs mutant ALSs, FUS proteins emerges from the nucleus and undergoes cytoplasmic localization. Here, FUS is linked to Alstrom syndrome.