11/15 (73%) SMA type I patients had one or two SMN2 copies, the remaining ones carrying 3 SMN2 copies, 10/12 (83%) type II patients carried three or four SMN2 copies, the remaining ones having 2 SMN2 copies, and 32/33 (96%) type III patients carried three or four SMN2 copies. The gene discussed is SMN2; the disease is spinal muscular atrophy, type 1.