METHODS: Case report forms were used to collect demographics; genetic confirmation; SMN2 copy number; treatment patterns; and clinical outcomes including ventilator use, endotracheal tube intubation, tracheostomy, gastrostomy, complications, and survival.
RESULTS: A total of 111 patients with SMA Type I were identified over the study period (1979-2015). Mean (median) age of onset and age at confirmed diagnosis were 1.3 (0.8) and 4.9 (4.4) months, respectively. SMN1 deletion/mutation was documented in 70 patients and SMN2 copy number in 32 (2 copies, n = 20; 3 copies, n = 12). At 240 months, survival probability for patients born during 1995-2015 versus 1979-1994 was significantly longer (p = 0.0057). Patients with 3 SMN2 copies showed substantially longer 240-month survival versus patients with 2 SMN2 copies. Over the 36-year period, mean (median) age at death was 31.9 (8.8) months. As of December 2015, 95 patients had died, 13 were alive, and 3 were lost to follow-up. The use of supportive measures (tracheostomy and gastrostomy) was associated with improved survival.
CONCLUSIONS: These data describe the short survival of patients with SMA Type I in Taiwan in the pretreatment era, emphasizing the positive impact of supportive measures on survival.