Congenital Myopathies 2

Abstract

CNMDU1 cases with the RYR1 mutation, RYR1 and triadin were similarly present in core-like areas that were located in the subsarcolemmal region in muscle fibers, while TOM20 was absent in that region. In contrast, 11 CNMDU1 cases without the RYR1 mutation and 3 MmD cases with SEPN1 , MYH7 and ACTA1 mutations respectively did not show this staining pattern, suggesting that the mechanism of core formation between CCD and MmD might be different. Notably, there was a significant correlation between the core position and the disease duration or progression-the older patients in more advanced stages had more centralized cores. Our results indicate that CNMDU1 due to RYR1 mutation is a de facto core myopathy, even though the cores are not remarkable on histochemistry.