SMN2 and proximal spinal muscular atrophy: The company compared data from the SPR1NT trial two-copy SMN2 cohort [17] with data from a cohort of patients in the PNCR dataset who had two copies of the SMN2 gene and type 1 SMA (n = 23), and compared data from the SPR1NT trial three-copy SMN2 cohort [18] with data from a cohort of patients in the PNCR dataset who had three copies of the SMN2 gene and any SMA type (n = 81).