Retrospective analysis of the natural history of type 1 spinal muscular atrophy in children

Objective. To analyze the natural course of type 1 spinal muscular atrophy in children with the onset of the disease up to 6 months in the Russian population.

Material and methods. The retrospective multicenter study included data of 54 children with an established diagnosis of type 1 spinal muscular atrophy who did not receive therapy with nusinersen, risdiplam, branaplam, onasemogen abeparvovec-xioi, or other anti-sense oligonucleotides / selective SMN2 splicing modifiers or genetherapy drugs for SMN1 genetransduction. Basedon medical records, the scientists have collected all available information on the health status of children, the need for respiratory support and death or start of long-term mechanical ventilation.

Results. The median time from birth to the onset of the combined event (death or initiation of long-term respiratory support), determined using the Kaplan-Meier method, was 365 [269; 409] days (12 months). The date of death was known in 22 out of 54 children. The median age of death was 301,5 [181; 375] days (9,9 months). The initiation date of long-term respiratory support was known in 15 of 54 patients, the median was 180 [91; 276] days (5,9 months). Both the start date of long-term respiratory support and the date of death were known in 5 of 54 children; whileit was found that the median time from the initiation of long-term respiratory support to death in these children was 361 [135; 619] day (11,87 months).In a subgroup of 32 children with available date of initiation of long-term respiratory support and / or the date of death, the median time from birth to the combined event was 245,5 [173; 331] days (8,07 months).

Conclusion. In the course of a retrospective study, the authors obtained the information on the date of the onset of constant respiratory support and the date of death from the date of birth in the absence of pathogenetic treatment in children with type 1 spinal muscular atrophy. The data obtained in the Russian population are comparable with the published international data. This information can be useful for additional assessment of the health status of patients who received drugs affecting the level of SMN protein in the body, as well as reference data for the development of new approaches to therapy.

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