Summary
One thousand two hundred fifty-five patients with SMA are currently followed in the Italian centers with an estimated prevalence of 2.12/100,000. Of the 1,255, 284 were type I, 470 type II, 467 type III, and 15 type IV with estimated prevalence of 0.48, 0.79, 0.79 and 0.02/100,000, respectively. Three patients with SMA 0 and 16 presymptomatic patients were also included
Original Article
Prevalence of Spinal Muscular Atrophy in the Era of Disease-Modifying Therapies
Neurology
Giorgia Coratti, Martina Ricci, Anna Capasso, Adele D'amico, Valeria Sansone, Claudio Bruno, Sonia Messina, Federica Ricci, Tiziana Mongini, Michela Coccia, Gabriele Siciliano, Elena Pegoraro, Mara Turri, Massimiliano Filosto, Giacomo Comi, Riccardo Masson, Lorenzo Maggi, Irene Bruno, Maria Grazia D'Angelo, Antonio Trabacca, Veria Vacchiano, Maria Donati, Isabella Simone, Lucia Ruggiero, Antonio Varone, Lorenzo Verriello, Angela Berardinelli, Caterina Agosto, Antonella Pini, Maria Antonietta Maioli, Luigia Passamano, Filippo Brighina, Nicola Carboni, Matteo Garibaldi, Riccardo Zuccarino, Delio Gagliardi, Sabrina Siliquini, Stefano Previtali, Domenica Taruscio, Stefania Boccia, Maria Carmela Pera, Marika Pane, Eugenio Mercuri, on behalf of ITASMAC working group
Abstract
Objective Spinal muscular atrophy (SMA) is a neurodegenerative disorder caused by mutations in the SMN1 gene. The aim of this study was to assess the prevalence of SMA and treatment prescription in Italy.
Methods An online survey was distributed to 36 centers identified by the Italian government as referral centers for SMA. Data on the number of patients with SMA subdivided according to age, type, SMN2 copy number, and treatment were collected.
Results One thousand two hundred fifty-five patients with SMA are currently followed in the Italian centers with an estimated prevalence of 2.12/100,000. Of the 1,255, 284 were type I, 470 type II, 467 type III, and 15 type IV with estimated prevalence of 0.48, 0.79, 0.79 and 0.02/100,000, respectively. Three patients with SMA 0 and 16 presymptomatic patients were also included. Approximately 85% were receiving one of the available treatments. The percentage of treated patients decreased with decreasing severity (SMA I: 95.77%, SMA II: 85.11%, SMA III: 79.01%).
Discussion The results provide for the first time an estimate of the prevalence of SMA at the national level and the current distribution of patients treated with the available therapeutical options. These data provide a baseline to assess future changes in relation to the evolving therapeutical scenario.
A recent review summarizing epidemiologic data on 5q spinal muscular atrophy (SMA) reported an overall incidence of 8/100,000, with a marked intercountry variability.1 Type I SMA cases are the most frequent (60%), with type II occurring between 20% and 27% and type III between 12% and 20%.1,2
Because of the reduced survival (approximately 5%–8% at 2 years), there is a large difference between incidence and prevalence data in type I infants. Studies performed before the advent of the new therapies report prevalence values of 0.04–0.28/100,000 for type I and approximately 1.5/100,000 for type II and III.3 The aim of the study was to assess the prevalence for SMA and the number of patients treated with the different therapeutic options across Italian reference centers.
Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.
