Pain interference and fatigue in limb-girdle muscular dystrophy R9.

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.

Cardiomyopathy in limb girdle muscular dystrophy R9, FKRP related.

INTRODUCTION: Reported frequencies of cardiomyopathy in limb girdle muscular dystrophy R9 (LGMDR9) vary. We describe the frequency and age at onset of cardiomyopathy in an LDMDR9 cohort. METHODS: Echocardiograms from 56 subjects (157 echocardiograms) with LGMDR9 were retrospectively reviewed. The cumulative probability of having an abnormal echocardiogram as a function of age was assessed by survival analysis for interval-censored data by genotype. Correlations between cardiac and clinical function were evaluated. RESULTS: Twenty-five (45%) participants had cardiomyopathy. The median age at first abnormal echocardiogram for subjects homozygous for the c.826C>A variant was 54.2 y compared to 18.1 y for all other fukutin-related protein (FKRP) genotypes (P < .0001). There was a weak correlation between ejection fraction and 10-Meter Walk Test speed (r = 0.25), but no correlation with forced vital capacity (r = 0.08). DISCUSSION: Cardiomyopathy is prevalent among those with LGMDR9 and occurs later in subjects homozygous for the c.826C>A mutation. These data will help to guide surveillance and management.

Motor outcome measures in patients with FKRP mutations: A longitudinal follow-up.

OBJECTIVE: To test the hypothesis that we will be able to detect change in motor outcome measures over time in a cohort with mutations in FKRP. METHODS: Individuals with documented FKRP mutations were evaluated annually with a battery of established motor outcome measures including limited quantitative myometry and timed function measures. Results were analyzed using random coefficient regression to determine annual change in each measure. Due to the nonlinear progression through the lifespan of the study participants, pediatric (<19 years) and adult (≥19 years) cohorts were analyzed separately. Effect of genotype was evaluated in each cohort. RESULTS: Sixty-nine participants (30 pediatric, 44 adult) with at least 2 evaluations were included. There was a small but statistically significant decline in timed motor function measures in both pediatric and adult cohorts. Genotype significantly affected rate of decline in the pediatric but not the adult cohort. Some pediatric patients who are homozygous for the c.826C>A mutation showed improving motor performance in adolescence. Performance on the 10-meter walk/run was highly correlated with other timed function tests. CONCLUSIONS: There is a slow annual decline in motor function in adults with FKRP mutations that can be detected with standard motor outcome measures, while the results in the pediatric population were more variable and affected by genotype. Overall, these analyses provide a framework for development of future clinical trials. The dystroglycanopathies natural history study (Clinical Trial Readiness for the Dystroglycanopathies) may be found on clinicaltrials.gov (NCT00313677).

Comparison of brain MRI findings with language and motor function in the dystroglycanopathies.

OBJECTIVE: To describe the spectrum of brain MRI findings in a cohort of individuals with dystroglycanopathies (DGs) and relate MRI results to function. METHODS: All available brain MRIs done for clinical indications on individuals enrolled in a DG natural history study (NCT00313677) were reviewed. Reports were reviewed when MRI was not available. MRIs were categorized as follows: (1) cortical, brainstem, and cerebellar malformations; (2) cortical and cerebellar malformations; or (3) normal. Language development was assigned to 1 of 3 categories by a speech pathologist. Maximal motor function and presence of epilepsy were determined by history or examination. RESULTS: Twenty-five MRIs and 9 reports were reviewed. The most common MRI abnormalities were cobblestone cortex or dysgyria with an anterior-posterior gradient and cerebellar hypoplasia. Seven individuals had MRIs in group 1, 8 in group 2, and 19 in group 3. Language was impaired in 100% of those in MRI groups 1 and 2, and degree of language impairment correlated with severity of imaging. Eighty-five percent of the whole group achieved independent walking, but only 33% did in group 1. Epilepsy was present in 8% of the cohort and rose to 37% of those with an abnormal MRI. CONCLUSIONS: Developmental abnormalities of the brain such as cobblestone lissencephaly, cerebellar cysts, pontine hypoplasia, and brainstem bowing are hallmarks of DG and should prompt consideration of these diagnoses. Brain imaging in individuals with DG helps to predict outcomes, especially language development, aiding clinicians in prognostic counseling.

Childhood Activity on Progression in Limb Girdle Muscular Dystrophy 2I.

Limb girdle muscular dystrophy 2I is a slowly progressive muscular dystrophy due to mutations in the Fukutin-related protein ( FKRP) gene. Clinicians are frequently asked if physical activity is harmful for pediatric patients with limb girdle muscular dystrophy 2I. The primary objective of this study was to determine if there is a relationship between self-reported childhood activity level and motor function and respiratory function in older children and adults with limb girdle muscular dystrophy 2I. We compared retrospective self-reported middle school activity level and sport participation with age at onset of weakness, 10-meter walk test, and forced vital capacity later in life in 41 participants with FKRP mutations. We found no relationship between activity level in childhood and disease course later in life, suggesting that self-directed physical activity in children with limb girdle muscular dystrophy 2I does not negatively affect disease progression and outcome.