A self-reported Brazilian registry of 5q-spinal muscular atrophy: data on natural history, genetic characteristics, and multidisciplinary care

• Published in: Arquivos de neuro-psiquiatria 2024-12, Vol.82 (12), p.1-9
• Main Authors: Mendonça, Rodrigo Holanda, Godoi, Juliane Suellen Arndt de, Zanoteli, Edmar
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Atrofia Muscular Espinal; Brazil; Child; Child, Preschool; Female; História Natural; Humans; Infant; Male; Middle Aged; Muscular Atrophy, Spinal; Muscular Atrophy, Spinal - genetics; Muscular Atrophy, Spinal - therapy; Mutation; Natural History; Proteína 1 de Sobrevivência do Neurônio Motor; Registries; Self Report; Sistema de Registros; Spinal Muscular Atrophies of Childhood - genetics; Spinal Muscular Atrophies of Childhood - physiopathology; Spinal Muscular Atrophies of Childhood - therapy; Survival of Motor Neuron 1 Protein; Survival of Motor Neuron 1 Protein - genetics; Young Adult
• ISSN: 0004-282X; 1678-4227; 1678-4227
• DOI: 10.1055/s-0044-1792096

Spinal muscular atrophy linked to chromosome 5q (SMA-5q) is a neurodegenerative disorder caused by mutations in the gene.  To describe the key demographic, clinical and genetic characteristics, as well as natural history data of patients with SMA-5q.  Up to January 2022, 706 patients with confirmed genetic diagnosis of SMA-5q, or their parents, completed a self-reported questionnaire on natural history, genetic characteristics, drug treatments, and multidisciplinary care.  Most patients had type 1 SMA-5q (42%); with 33% having type 2, and 23% type 3. There were 667 patients (94.4%) with a homozygous -exon 7 deletion. Of the total, 131 (18.6%) patients had a previous family history of the disease, and the familial recurrence rate was higher in type 3 (25.6%). Type 1 patients had a mean age of 3 months at the onset of symptoms and a delay of more than 3 months until genetic diagnosis. The median survival of patients with type 1 without invasive ventilation was 27 months. Before 2018, the median age of use of invasive ventilation was 16 months and, after, most patients (71%) were not submitted to invasive ventilation. About 50% of patients with type 3 lost their walking ability by 37 years of age. Further, 384 (54.4%) patients had access to disease-modifying therapy, and 62.3% of type 1 patients were in treatment, compared with only 47.2% of type 2 and 31.9% of type 3 patients.  There is still a substantial diagnostic delay, especially in those patients with types 2 and 3 SMA-5q. However, the present study demonstrated prolonged survival, especially in type 1 patients.