SMN1 and proximal spinal muscular atrophy: All patients were diagnosed with 5q SMA according to molecular tests, consisting of 389 patients with homozygous deletion of exon 7 in the SMN1 gene (389/392, 99.2%), and 3 cases with a point mutation of the SMN1 gene coexisting with a deletion (3/392, 0.8%), including one SMA 1a patient with a splicing mutation (NM_000344.3: c.835-1G>A), one SMA 1c patient with a missense mutation [NM_000344.3: c.835G>C (p.Gly279Arg)], and one SMA 3a patient with a missense mutation [NM_000344.3: c.863G>T (p.Gly279Glufs*5)].