- Email: [email protected]
G.P.57 Differential proteomic analysis of protein aggregates in desminopathy
Abstracts / Neuromuscular Disorders 22 (2012) 804–908 BAG3, but not WT, were accumulated in some muscle fibers, although all transgenic BAG3 were predominantly detected as striated patterns. Similar to the human patients’ muscles, accumulations of BAG3 were co-localized with other Z-line proteins such as Filamin C and Desmin. Our results strongly suggested that the p.261_265RAASPdel is a causative mutation of BAG3opathy. Transgenic medaka is a useful model for evaluating pathogenicity of human mutation. http://dx.doi:10.1016/j.nmd.2012.06.065
G.P.56 Novel homozygous stop mutation in alphaB crystallin: Expanding the phenotype C. Tesi Rocha 1, M. Taylor 1, T. Chang 1, C. Reyes 1, T. Winder 2, S. Moore 3, C. Bonnemann 4, K. Nelson 1 1 Children’s National Medical Center, Washington, DC, United States; 2 Prevention Genetics, Marshfield, WI, United States; 3 University of Iowa, Iowa City, IA, United States; 4 National Institutes of Health, Bethesda, MD, United States Mutations in the CRYAB gene, encoding alpha-B crystalline cause different phenotypes including myofibrillar myopathy, cardiomyopathy, isolated cataract and a multisystemic disorder. Even if genotype–phenotype association is still unclear, previously reported autosomal recessive mutations in the alphaB crystallin (CRYAB) has been associated with a fatal hypertonic infantile muscular dystrophy, in association with two different CRYAB stop mutations, p.S21AfsX24, p.S115PfsX14. Here we present two children from a non-consanguineous family, originally from Ghana, who were homozygous for a third CRYAB stop mutation, c.404C>A, p.Ser135X. The proband presented with respiratory distress one week after routine two month-old vaccinations and rapidly progressed into respiratory failure due to extreme general muscle rigidity. Serum CK was 772 U/L. EMG unremarkable and GLRA1 testing for stiffbaby syndrome was negative. Myofibrillary myopathy was suspected and targeted gene sequence analysis of CRYAB returned positive. The parents elected to withdrawal support and a muscle biopsy was performed. An older sister had a similar presentation after routine two month-old vaccinations to a local hospital and died at 18 months of age without a diagnosis. Myopathic features observed in the muscle biopsy using routine histochemistry and enzyme histochemistry were mild and nonspecific. However, small inclusion bodies were detected using antibodies against alphaB crystallin and myotilin. A second alphaB crystallin antibody (C-terminus epitope) failed to detect the inclusion bodies. This new case of recessive MFM expands the phenotype showing a fatal form of the disease with milder myopathic features on muscle biopsy than the two previously reported autosomal recessive fatal cases. http://dx.doi:10.1016/j.nmd.2012.06.066
G.P.57 Differential proteomic analysis of protein aggregates in desminopathy A. Maerkens 1, R.A. Kley 2, A. Schreiner 2, V. Theis 1, T. Mueller 1, M. Vorgerd 2, K. Marcus 1 1 Ruhr-University Bochum, Department of Functional Proteomics, Medical Proteome Center, Bochum, Germany; 2 Ruhr-University Bochum, Department of Neurology, University Hospital Bergmannsheil, Bochum, Germany Desminopathy is a subtype of myofibrillar myopathies (MFM) caused by mutations in DES, the gene encoding desmin. A histopathologic hallmark of the disease is a massive protein aggregation within skeletal muscle
821
fibers. The aim of our study was to elucidate the composition of aggregates in MFM patients with different desmin mutations by using a label-free mass spectrometry approach. Aggregates and control tissue from muscle biopsies of MFM patients with four different mutations in DES were collected by laser microdissection and analyzed by a combination of mass-spectrometry and spectral index calculation. Proteins with a ratio >1.8 (sum of peptides identified in aggregates compared to intraindividual controls) were accepted as accumulated in aggregates. Results of selected proteins were validated by immunofluorescence studies. Mass spectrometric data were searched against an extended human protein database to detect desmin mutations at the protein level. Three hundred and seventeen different proteins were identified and 98 of them showed an accumulation in aggregates. Aggregate compositions were more heterogenous than in other MFM subtypes, depending on individual mutations, but desmin was on top of the list of abundant proteins in all cases except of one. Immunolocalization findings were consistent with proteomic data. Three out of four desmin mutations were identified at the protein level. Our proteomic approach enabled the identification of many novel components of pathologic protein aggregates within skeletal muscle fibers of desminopathy patients. This provides new insights in the pathogenesis of the disease. Differences in aggregate composition in patients with different desmin mutations indicate diverse pathomechanisms, consistent with data of previous functional studies. http://dx.doi:10.1016/j.nmd.2012.06.067
G.P.58 Muscle MRI in a filaminopathy family: Involvement of paraspinals is earlier and more severe than of thigh muscles A. Ozturk Yavuz 1, L. Goldfarb 2, O. Tuncer 3, M. Dursun 4, M. Olive 5, F. Deymeer 6, Y. Parman 6, R. Tuncay 6, P. Serdaroglu-Oflazer 6 1 Istanbul Gaziosmanpasa Hospital, Neurology, Istanbul, Turkey; 2 National Institute of Health, Clinical Neurogenetic Unit, Bethesda, United States; 3 Bilim University, Medical Faculty, Neurology, Istanbul, Turkey; 4 University of Istanbul, Istanbul Medical Faculty, Radiology, Istanbul, Turkey; 5 IDIBELL-Hospital Universitari de Bellvitge, Institut de Neuropatologia, Barcelona, Spain; 6 University of Istanbul, Istanbul Medical Faculty, Neurology, Istanbul, Turkey Mild to severe weakness of proximal and distal limb muscles is common in all types of myofibrillar myopathies (MFM). In clinical practice, it is important to know the specific distribution patterns of muscle involvement in order to differentiate the various subtypes. Muscle MRI is a useful tool to show the distribution and severity of muscle involvement in different muscle diseases. Here we report two patients with p.W2710X in FLNC gene mutation from a Macedonian family with 18 affected members. The patients were a male at 55 and a female at 51 years of age with 14 and 8 years of disease duration, respectively. The onset symptom in both patients was difficulty in holding the waist up upon rising from a chair or climbing stairs. Muscle strength evaluation revealed that the most severely affected muscles were the lower extremity proximal and the trunk muscles in each patient without a significant difference in weakness distribution pattern. Muscle MRI scans for thigh, pelvic and lower paraspinal muscles were performed. Regardless of the duration of the disease the most severely affected muscles were the paraspinals, practically almost totally replaced by fat in both patients. Although to a slightly lesser degree, another relatively severely affected group was the posterior thigh muscles. Involvement in this latter group and in even the less affected gluteus maximus showed correlation with the disease duration. Anterior thigh compartment muscles seemed to remain relatively spared. Filaminopathy has not been listed among the myopathies that predominantly involve the trunk muscles. Although more reports are needed, our experience in two patients suggests that
G.P.56 Novel homozygous stop mutation in alphaB crystallin: Expanding the phenotype C. Tesi Rocha 1, M. Taylor 1, T. Chang 1, C. Reyes 1, T. Winder 2, S. Moore 3, C. Bonnemann 4, K. Nelson 1 1 Children’s National Medical Center, Washington, DC, United States; 2 Prevention Genetics, Marshfield, WI, United States; 3 University of Iowa, Iowa City, IA, United States; 4 National Institutes of Health, Bethesda, MD, United States Mutations in the CRYAB gene, encoding alpha-B crystalline cause different phenotypes including myofibrillar myopathy, cardiomyopathy, isolated cataract and a multisystemic disorder. Even if genotype–phenotype association is still unclear, previously reported autosomal recessive mutations in the alphaB crystallin (CRYAB) has been associated with a fatal hypertonic infantile muscular dystrophy, in association with two different CRYAB stop mutations, p.S21AfsX24, p.S115PfsX14. Here we present two children from a non-consanguineous family, originally from Ghana, who were homozygous for a third CRYAB stop mutation, c.404C>A, p.Ser135X. The proband presented with respiratory distress one week after routine two month-old vaccinations and rapidly progressed into respiratory failure due to extreme general muscle rigidity. Serum CK was 772 U/L. EMG unremarkable and GLRA1 testing for stiffbaby syndrome was negative. Myofibrillary myopathy was suspected and targeted gene sequence analysis of CRYAB returned positive. The parents elected to withdrawal support and a muscle biopsy was performed. An older sister had a similar presentation after routine two month-old vaccinations to a local hospital and died at 18 months of age without a diagnosis. Myopathic features observed in the muscle biopsy using routine histochemistry and enzyme histochemistry were mild and nonspecific. However, small inclusion bodies were detected using antibodies against alphaB crystallin and myotilin. A second alphaB crystallin antibody (C-terminus epitope) failed to detect the inclusion bodies. This new case of recessive MFM expands the phenotype showing a fatal form of the disease with milder myopathic features on muscle biopsy than the two previously reported autosomal recessive fatal cases. http://dx.doi:10.1016/j.nmd.2012.06.066
G.P.57 Differential proteomic analysis of protein aggregates in desminopathy A. Maerkens 1, R.A. Kley 2, A. Schreiner 2, V. Theis 1, T. Mueller 1, M. Vorgerd 2, K. Marcus 1 1 Ruhr-University Bochum, Department of Functional Proteomics, Medical Proteome Center, Bochum, Germany; 2 Ruhr-University Bochum, Department of Neurology, University Hospital Bergmannsheil, Bochum, Germany Desminopathy is a subtype of myofibrillar myopathies (MFM) caused by mutations in DES, the gene encoding desmin. A histopathologic hallmark of the disease is a massive protein aggregation within skeletal muscle
821
fibers. The aim of our study was to elucidate the composition of aggregates in MFM patients with different desmin mutations by using a label-free mass spectrometry approach. Aggregates and control tissue from muscle biopsies of MFM patients with four different mutations in DES were collected by laser microdissection and analyzed by a combination of mass-spectrometry and spectral index calculation. Proteins with a ratio >1.8 (sum of peptides identified in aggregates compared to intraindividual controls) were accepted as accumulated in aggregates. Results of selected proteins were validated by immunofluorescence studies. Mass spectrometric data were searched against an extended human protein database to detect desmin mutations at the protein level. Three hundred and seventeen different proteins were identified and 98 of them showed an accumulation in aggregates. Aggregate compositions were more heterogenous than in other MFM subtypes, depending on individual mutations, but desmin was on top of the list of abundant proteins in all cases except of one. Immunolocalization findings were consistent with proteomic data. Three out of four desmin mutations were identified at the protein level. Our proteomic approach enabled the identification of many novel components of pathologic protein aggregates within skeletal muscle fibers of desminopathy patients. This provides new insights in the pathogenesis of the disease. Differences in aggregate composition in patients with different desmin mutations indicate diverse pathomechanisms, consistent with data of previous functional studies. http://dx.doi:10.1016/j.nmd.2012.06.067
G.P.58 Muscle MRI in a filaminopathy family: Involvement of paraspinals is earlier and more severe than of thigh muscles A. Ozturk Yavuz 1, L. Goldfarb 2, O. Tuncer 3, M. Dursun 4, M. Olive 5, F. Deymeer 6, Y. Parman 6, R. Tuncay 6, P. Serdaroglu-Oflazer 6 1 Istanbul Gaziosmanpasa Hospital, Neurology, Istanbul, Turkey; 2 National Institute of Health, Clinical Neurogenetic Unit, Bethesda, United States; 3 Bilim University, Medical Faculty, Neurology, Istanbul, Turkey; 4 University of Istanbul, Istanbul Medical Faculty, Radiology, Istanbul, Turkey; 5 IDIBELL-Hospital Universitari de Bellvitge, Institut de Neuropatologia, Barcelona, Spain; 6 University of Istanbul, Istanbul Medical Faculty, Neurology, Istanbul, Turkey Mild to severe weakness of proximal and distal limb muscles is common in all types of myofibrillar myopathies (MFM). In clinical practice, it is important to know the specific distribution patterns of muscle involvement in order to differentiate the various subtypes. Muscle MRI is a useful tool to show the distribution and severity of muscle involvement in different muscle diseases. Here we report two patients with p.W2710X in FLNC gene mutation from a Macedonian family with 18 affected members. The patients were a male at 55 and a female at 51 years of age with 14 and 8 years of disease duration, respectively. The onset symptom in both patients was difficulty in holding the waist up upon rising from a chair or climbing stairs. Muscle strength evaluation revealed that the most severely affected muscles were the lower extremity proximal and the trunk muscles in each patient without a significant difference in weakness distribution pattern. Muscle MRI scans for thigh, pelvic and lower paraspinal muscles were performed. Regardless of the duration of the disease the most severely affected muscles were the paraspinals, practically almost totally replaced by fat in both patients. Although to a slightly lesser degree, another relatively severely affected group was the posterior thigh muscles. Involvement in this latter group and in even the less affected gluteus maximus showed correlation with the disease duration. Anterior thigh compartment muscles seemed to remain relatively spared. Filaminopathy has not been listed among the myopathies that predominantly involve the trunk muscles. Although more reports are needed, our experience in two patients suggests that