Late onset dysferlinopathy is associated with a less severe and more atypical disease phenotype, with milder dystrophic changes on muscle biopsy and greater time from symptom onset to loss of ambulation compared to early onset disease.
Why this matters
Dysferlinopathies are autosomal recessive neuromuscular disorders caused by mutations in the DYSF gene. There is significant variability in the clinical presentation of dysferlinopathies, with no clear genotype-phenotype correlation.
Symptom onset typically occurs early in life (early onset; between the age of 10 and 30 years), but a subgroup of people with late onset dysferlinopathy (over the age of 30) is also known. Differences in age of onset are believed to contribute to the clinical heterogeneity of dysferlinopathies. However, late onset disease is not well characterized.