Pain is prevalent in individuals with limb-girdle muscular dystrophy (LGMD) R9, but impact on daily living and correlation with fatigue remain unknown. Patient-Reported Outcomes Measurement Information System (PROMIS) pain interference and fatigue short forms were completed annually by 23 children and 54 adults with biallelic fukutin-related protein (FKRP) variants for up to six years. Concurrent motor and pulmonary function were evaluated. Pain interference T-scores were near the normal mean of 50 by linear mixed model analysis (48.5 in children, 51.6 in adults). 58% of participants experienced pain interference levels greater than the general population on at least one assessment. Fatigue T-scores were elevated in adults but not children (49.0 in children, 55.1 in adults), and 75% had at least one elevated fatigue score. Of participants with at least two visits, serial scores were not consistent across visits, without a clear pattern. Pain interference and fatigue were positively correlated (r = 0.55). Both increased with older age (r = 0.21 and 0.41 respectively). Neither differed by sex or ambulation status. Motor (r=-0.32) and pulmonary (r=-0.25) function correlated with fatigue in adults, not children. Results suggest that pain in those with LGMDR9 is variable and episodic, limiting impact on daily life, while fatigue increases over time.
Keywords: 10-meter walk/run; 6-minute walk test; FKRP; Motor function; PROMIS short form; Pulmonary function.
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