title: Protein and gene analyses of dysferlinopathy in a large group of Japanese muscular dystrophy patients.
abstract: Mutations in the dysferlin gene cause muscular dystrophies called dysferlinopathy, which include limb-girdle muscular dystrophy type 2B (LGMD2B) and Miyoshi myopathy (MM). To clarify the frequency, clinicopathological and genetic features of dysferlinopathy in Japan, we performed protein and gene analyses of dysferlin. We examined a total of 107 unrelated Japanese patients, including 53 unclassified LGMD, 28 MM and 26 other neuromuscular disorders (ONMD). Expression of dysferlin protein was observed using immunohistochemistry (IHC) and mini-multiplex Western blotting (MMW), and mutation analysis was performed. We found a deficiency of dysferlin protein by both IHC and MMW in 19% of LGMD and 75% of MM patients, and mutations in the dysferlin gene were identified in this group alone. 19% of dysferlin-deficient patients had 3370G-->T missense mutation and 16% had 1939C-->G nonsense mutation. The patients with homozygous 3370G-->T mutation showed milder clinical phenotypes. Twenty-five percent of MM muscles had normal dysferlin protein contents that suggested the genetic heterogeneity of this disease. Altered immunolocalization of dysferlin was observed in not only primary dysferlinopathy, but also in the several diseased muscles with normal protein contents. This result implies the necessity of other protein(s) for proper membrane localization of dysferlin, or some roles of dysferlin in the cytoplasmic region.
authors.affiliation: Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Tagawa
authors.forename: Megumu
authors.initials: M
authors.lastname: Ogawa
authors.forename: Kiyokazu
authors.initials: K
authors.lastname: Kawabe
authors.forename: Gaku
authors.initials: G
authors.lastname: Yamanaka
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Matsumura
authors.forename: Kanako
authors.initials: K
authors.lastname: Goto
authors.forename: Ikuya
authors.initials: I
authors.lastname: Nonaka
authors.forename: Ichizo
authors.initials: I
authors.lastname: Nishino
authors.forename: Yukiko K
authors.initials: YK
authors.lastname: Hayashi
mesh_terms: D017668:Age of Onset; D000409:Alanine / Q000235:genetics; D015153:Blotting, Western; D002154:Calpain / Q000378:metabolism; D003545:Cysteine / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004252:DNA Mutational Analysis; D000073939:Dysferlin; D049030:Dystroglycans; D016189:Dystrophin / Q000378:metabolism; D005998:Glycine / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D007564:Japan / Q000453:epidemiology; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins; D009124:Muscle Proteins / Q000235:genetics* / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism; D009136:Muscular Dystrophies / Q000145:classification / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D009468:Neuromuscular Diseases / Q000235:genetics / Q000378:metabolism; D049031:Sarcoglycans; D020539:Sequence Analysis, Protein; D014443:Tyrosine / Q000235:genetics
chemical_list: D003598:Cytoskeletal Proteins; C483081:DAG1 protein, human; C114839:DYSF protein, human; D000073939:Dysferlin; D016189:Dystrophin; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009124:Muscle Proteins; D049031:Sarcoglycans; D049030:Dystroglycans; D014443:Tyrosine; D002154:Calpain; C078134:calpain p94; D003545:Cysteine; D000409:Alanine; D005998:Glycine