This study analyzed the presence of genetic markers of SMN1 duplication, c.*3+80T>G and c.*211_*212del, in a cohort of 158 Russian residents carrying SMN1 du-plication (population cohort and 15 parents of 5q SMA patients with two copies of SMN1), as well as in 209 unrelated Russian residents with one copy of SMN1. This evidence concerns the gene SMN1 and proximal spinal muscular atrophy.