Spinal Muscular Atrophy (SMA) is a progressive degenerative neuromuscular disease that can cause several motor, respiratory, and functional impairments, directly interfering with the quality of life (QoL). Depending on the severity of the SMA, the individual may need intermittent care and their caregivers may feel overwhelmed with this responsibility.

To correlate caregiver burden and motor function measurement (MFM) of individuals with SMA with their QoL.

Descriptive cross-sectional study, carried out in a state rehabilitation center in Goiânia, Goiás, Brazil. Data collection was carried out from March to July 2022, consisting of individuals diagnosed with SMA types I, II, and III being followed up at the institution's Neuromuscular Diseases Clinic and their main family caregivers. To analyze the MFM, participants younger than six years old were evaluated using the Motor Function Measurement Scale - Short Version (MFM-20), and those older than six years old using the Motor Function Measurement Scale (MFM-32). For QoL assessment, those over five years old answered the PedsQL Neuromuscular 3.0 questionnaire according to age group, while those under five years old had the same questionnaire answered by their guardians. To assess caregiver burden, the Burden Interview questionnaire was used. The distribution of demographic profile and clinical data was tested according to the type of SMA by applying Pearson's Chi-square test and “Post hoc” standardized residual analysis. The QoL, MFM, and caregiver burden were tested between the types of EBF using the Analysis of Covariance (ANCOVA), controlling the effect of variables that presented p < 0.05 in the initial exploratory analyses. The significance level adopted was p < 0.05.

The sample consisted of 32 individuals with SMA, 6(18.7%) type I, 9(28.1%) type II, and 17(53.1%) type III, with a mean age of 21.9± 17.3 years old, mostly male 17(53.1%) and 27 caregivers, 26(96.3%) females. The MFM showed a moderate positive correlation with the QoL of individuals with SMA type II (r = 0.71; p = 0.05) and in type III it had a strong positive correlation with statistical significance (r = 0.63; p = 0. 01). Caregiver burden had a negative correlation with QoL in SMA types II and III (r = - 0.71; p = 0.05 and r = -0.16; p = 0.63, respectively), without statistical significance.

MFM correlated with the QoL of individuals with SMA, especially type III. The burden of caregivers showed a negative relationship with the QoL of people with SMA, highlighting the need for care for this population.

Knowledge of the motor function of individuals with SMA and the burden of their caregivers are important aspects that allow for more specific therapeutic approaches according to their individualities.