RYR1 and congenital myopathy with cores: Minicores as a non-specific finding on muscle biopsy have been reported in healthy probands following eccentric exercise (i.e., lengthening during activity) [62] and on muscle biopsies from families with MH susceptibility due to RYR1 mutations but no other clinical features of a congenital myopathy [30,31]; they may occur in other contexts such as dystrophy, denervation, inflammatory and endocrine myopathies [for review, [1]] and primarily metabolic conditions such as type III glycogenosis [63] or short-chain acyl-CoA dehydrogenase (SCAD) deficiency [64].