SMN2 and proximal spinal muscular atrophy: A total of 3 SNPs in NAIP, namely G-711A was found to be most significant with identification in SMA type II = 3 copies of SMN2, T-1040A was found to be most significant with identification in SMA type I = 1 copy of SMN2 with NAIP 5 deletion and T-1058A was found in SMA patients as (Type 1 equals two copies of SMN2, while Type II equals three copies of SMN2).