Late-onset axial myopathy with cores due to a novel heterozygous dominant mutation in the skeletal muscle ryanodine receptor (RYR1) gene

This case expands the spectrum of RYR1-related phenotypes and suggests that MH-related RYR1 mutations may give rise to overt neuromuscular symptoms later in life, with clinical features not typically found in CCD due to C-terminal hotspot mutations. Late-onset congenital myopathies may be under-recognised and diagnosis requires a high degree of clinical suspicion.