Claudio Semplicini1, Cinzia Bertolin1, Luca Bello1, Boris Pantic1, Francesca Guidolin1, Sara Vianello1, Francesco Catapano1, Irene Colombo1, Maurizio Moggio1, Bruno F Gavassini1, Giovanna Cenacchi1, Valentina Papa1, Marco Previtero1, Chiara Calore1, Gianni Sorarù1, Giovanni Minervini1, Silvio C E Tosatto1, Roberto Stramare1, Elena Pegoraro2. 1. From the Neuromuscular Center (C.S., C.B., L.B., B.P., F.G., S.V., B.F.G., G.S., E.P.), Department of Neurosciences, and Departments of Cardiac, Thoracic and Vascular Sciences (M.P., C.C.), Biomedical Sciences (G.M., S.C.E.T.), and Medicine (R.S.), Section of Radiology, University of Padova, Italy; Dubowitz Neuromuscular Centre (Developmental Neuroscience Programme) (F.C.), UCL Great Ormond Street Institute of Child Health, University College London, UK; Neuromuscular and Rare Disease Unit (I.C., M.M.), Department of Neuroscience, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan; Department of Biomedical and Neuromotor Sciences (G.C., V.P.), University of Bologna; and CNR Institute of Neuroscience (S.C.E.T.), Padova, Italy. 2. From the Neuromuscular Center (C.S., C.B., L.B., B.P., F.G., S.V., B.F.G., G.S., E.P.), Department of Neurosciences, and Departments of Cardiac, Thoracic and Vascular Sciences (M.P., C.C.), Biomedical Sciences (G.M., S.C.E.T.), and Medicine (R.S.), Section of Radiology, University of Padova, Italy; Dubowitz Neuromuscular Centre (Developmental Neuroscience Programme) (F.C.), UCL Great Ormond Street Institute of Child Health, University College London, UK; Neuromuscular and Rare Disease Unit (I.C., M.M.), Department of Neuroscience, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan; Department of Biomedical and Neuromotor Sciences (G.C., V.P.), University of Bologna; and CNR Institute of Neuroscience (S.C.E.T.), Padova, Italy. elena.pegoraro@unipd.it.
Abstract
OBJECTIVE: To identify and characterize patients with calsequestrin 1 (CASQ1)-related myopathy. METHODS: Patients selected according to histopathologic features underwent CASQ1 genetic screening. CASQ1-mutated patients were clinically evaluated and underwent muscle MRI. Vacuole morphology and vacuolated fiber type were characterized. RESULTS: Twenty-two CASQ1-mutated patients (12 families) were identified, 21 sharing the previously described founder mutation (p.Asp244Gly) and 1 with the p.Gly103Asp mutation. Patients usually presented in the sixth decade with exercise intolerance and myalgias and later developed mild to moderate, slowly progressive proximal weakness with quadriceps atrophy and scapular winging. Muscle MRI (n = 11) showed a recurrent fibrofatty substitution pattern. Three patients presented subclinical cardiac abnormalities. Muscle histopathology in patients with p.Asp244Gly showed vacuoles in type II fibers appearing empty in hematoxylin-eosin, Gomori, and nicotinamide adenine dinucleotide (NADH) tetrazolium reductase stains but strongly positive for sarcoplasmic reticulum proteins. The muscle histopathology of p.Gly103Asp mutation was different, showing also NADH-positive accumulation consistent with tubular aggregates. CONCLUSIONS: We report the clinical and molecular details of the largest cohort of CASQ1-mutated patients. A possible heart involvement is presented, further expanding the phenotype of the disease. One mutation is common due to a founder effect, but other mutations are possible. Because of a paucity of symptoms, it is likely that CASQ1 mutations may remain undiagnosed if a muscle biopsy is not performed.
OBJECTIVE: To identify and characterize patients with calsequestrin 1 (CASQ1)-related myopathy. METHODS:Patients selected according to histopathologic features underwent CASQ1 genetic screening. CASQ1-mutated patients were clinically evaluated and underwent muscle MRI. Vacuole morphology and vacuolated fiber type were characterized. RESULTS: Twenty-two CASQ1-mutated patients (12 families) were identified, 21 sharing the previously described founder mutation (p.Asp244Gly) and 1 with the p.Gly103Asp mutation. Patients usually presented in the sixth decade with exercise intolerance and myalgias and later developed mild to moderate, slowly progressive proximal weakness with quadriceps atrophy and scapular winging. Muscle MRI (n = 11) showed a recurrent fibrofatty substitution pattern. Three patients presented subclinical cardiac abnormalities. Muscle histopathology in patients with p.Asp244Gly showed vacuoles in type II fibers appearing empty in hematoxylin-eosin, Gomori, and nicotinamide adenine dinucleotide (NADH) tetrazolium reductase stains but strongly positive for sarcoplasmic reticulum proteins. The muscle histopathology of p.Gly103Asp mutation was different, showing also NADH-positive accumulation consistent with tubular aggregates. CONCLUSIONS: We report the clinical and molecular details of the largest cohort of CASQ1-mutated patients. A possible heart involvement is presented, further expanding the phenotype of the disease. One mutation is common due to a founder effect, but other mutations are possible. Because of a paucity of symptoms, it is likely that CASQ1 mutations may remain undiagnosed if a muscle biopsy is not performed.
Authors: Andrew M Waterhouse; James B Procter; David M A Martin; Michèle Clamp; Geoffrey J Barton Journal: Bioinformatics Date: 2009-01-16 Impact factor: 6.937