[Results in our symptomatic and presymptomatic SMA patients treated with disease-modifying therapy]

Abstract

Background and purpose: The aim of this study was the comparison of the movement development, instrumental breathing and feeding support, and hospital care needs of children with SMA (spinal muscular atrophy) who received disease-modifying therapy in the presymptomatic and symptomatic stages.

Methods: At the Bethesda Children's Hospital, between October 2019 and March 2024, the pre- and post-treatment condition of children receiving disease-modifying therapy for SMA, both in symptomatic and presymptomatic stages, was examined based on ret- rospective data collection and statistical analysis.

Results: During the examined period, 34 children received gene replacement treatment for SMA. In the 28 patients of group I, SMA was diagnosed based on symptoms at an average age of 7.47 (1.6-27) months, and their disease-modifying therapy began at 9.51 (2.0-31.0) months of age. In the II. group 6 patients were diagnosed with neonatal SMA screening at an average age of 15.83 (10-27) and therapy at 32.16 (22-48) days of age. Based on the health assessment conducted at the age of 3.08 (0.34-5.65), the number of patients requiring daily respiratory support did not change, the number of those requiring ventilation for each sleep was reduced by half, and the ability to swallow returned to 3 patients. The previously existing movement deficit in all patients showed partial improvement in 22 (78.57%) children, stagnated in 4 patients, and progressed in 2 children. The scale measuring the movement spectrum of patients unable to sit increased by an average of 14.62 (6-29) points. The scale examining children who are able to sit could be examined in 7 patients before therapy and in 16 patients during control; average increased by 8.36 (2-45) points. 39.28% of the patients (n = 11) requested hospital care a total of 31 times due to acute deterioration. One patient died at home at the age of 3.2 years (22 months after gene therapy). The 6 patients of the II. group at an average age of 0.88 (0.25-1.07) did not require instrumental breathing and/or feeding support, the movement development of the five 3 SMN (Survival Motor Neuron)2-copy patients followed that of their healthy peers. A newborn with 2 copies of SMN2, starting with a score of 54, had slower motor development and a 6-point increase, unable to sit independently at one year of age.

Conclusion: The diagnosis of SMA should be considered as a neurological emergency both from the point of view of diagnosis and initiation of therapy. The only way to prevent progression and irreversible loss of function is automatic screening of the disease for the entire newborn population and early treatment. The absence of symptoms or only minimally suboptimal development achieved through early diagnosis and disease-modifying therapy, a lifestyle that is not confined to bed, and technology independence are health benefits for the individual, family and society alike.The diagnosis of SMA should be considered as a neurological emergency both from the point of view of diagnosis and initiation of therapy. The only way to prevent progression and irreversible loss of function is automatic screening of the disease for the entire newborn population and early treatment. The absence of symptoms or only minimally suboptimal development achieved through early diagnosis and disease-modifying therapy, a lifestyle that is not confined to bed, and technology independence are health benefits for the individual, family and society alike.

Keywords: disease-modifying therapies; movement development; neonatal screening; spinal muscular atrophy; technology dependence.