Young-Eun Park1,2, Jin-Hong Shin1,3, Boram Kang3, Chang-Hoon Lee2,4, Dae-Seong Kim1,3. 1. Department of Neurology, Pusan National University Yangsan Hospital, Beomo-ri, Mulgeum-eup, Yangsan, 626-770, Gyeongnam, South Korea. 2. Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea. 3. Research Institute for Convergence of Biomedical Research and Technology, Pusan National University Yangsan Hospital, Gyeongnam, South Korea. 4. Department of Pathology, Pusan National University, Busan, South Korea.
Abstract
INTRODUCTION: Mutations in the gene encoding nebulin (NEB) are known to cause several types of congenital myopathy including recessive nemaline myopathy and distal nebulin myopathy. Core-rod myopathy has recently been reported to be another type of NEB-related myopathy, and is pathologically characterized by the coexistence of cores and nemaline rods within muscle fibers. METHODS: We describe 2 patients with core-rod myopathy who were analyzed genetically by whole exome sequencing and evaluated clinically and pathologically. Findings were compared with those of patients with the disease of other genetic causes. RESULTS: Three NEB mutations were identified, 2 of which were novel. Mild clinical features, unusual patterns of muscle involvement, and atypical pathological findings were observed. CONCLUSIONS: We propose that the clinical and pathological spectrum of core-rod myopathy should be widened. A significant amount of residual nebulin expression is believed to contribute to the much milder phenotype exhibited by the patients we describe here.
INTRODUCTION: Mutations in the gene encoding nebulin (NEB) are known to cause several types of congenital myopathy including recessive nemaline myopathy and distal nebulinmyopathy. Core-rod myopathy has recently been reported to be another type of NEB-related myopathy, and is pathologically characterized by the coexistence of cores and nemaline rods within muscle fibers. METHODS: We describe 2 patients with core-rod myopathy who were analyzed genetically by whole exome sequencing and evaluated clinically and pathologically. Findings were compared with those of patients with the disease of other genetic causes. RESULTS: Three NEB mutations were identified, 2 of which were novel. Mild clinical features, unusual patterns of muscle involvement, and atypical pathological findings were observed. CONCLUSIONS: We propose that the clinical and pathological spectrum of core-rod myopathy should be widened. A significant amount of residual nebulin expression is believed to contribute to the much milder phenotype exhibited by the patients we describe here.
Authors: Szabolcs Szelinger; Jonida Krate; Keri Ramsey; Samuel P Strom; Perry B Shieh; Hane Lee; Newell Belnap; Chris Balak; Ashley L Siniard; Megan Russell; Ryan Richholt; Matt De Both; Ana M Claasen; Isabelle Schrauwen; Stanley F Nelson; Matthew J Huentelman; David W Craig; Samuel P Yang; Steven A Moore; Kumaraswamy Sivakumar; Vinodh Narayanan; Sampathkumar Rangasamy Journal: Neurol Genet Date: 2020-06-30