SOD1 and Respiratory insufficiency: Overall, except for the homozygous D91A mutation, known to display a slower course [5,11], most of the mutations were associated with an aggressive evolution: two thirds of patients presented respiratory insufficiency and the median survival time was only two years, which is shorter than the median disease duration of three years previously reported in France [9], but in line with the largest SOD1 cohort to date [11].