title: Analysis of histopathologic and molecular pathologic findings in Czech LGMD2A patients.
abstract: Limb-girdle muscular dystrophy type 2A (LGMD2A) is an autosomal-recessive disorder characterized by selective atrophy and progressive weakness of proximal girdle muscles. LGMD2A, the most prevalent form of LGMD, is caused by mutations in the CAPN3 gene that encodes the skeletal muscle-specific member of the calpain family, calpain-3 (p 94). We examined the histopathologic and molecular pathologic findings in 14 Czech LGMD2A patients. Analysis of the CAPN3 gene was performed at the mRNA level, using reverse transcription-polymerase chain reaction (RT-PCR) and sequencing, and/or DNA level, using PCR and denaturing high-performance liquid chromatography (DHPLC). Our results confirm that mutation 550 delA is the most frequent CAPN3 defect in Czech LGMD2A patients (9 alleles of 28). Furthermore, we established that, in a patient with the 550 delA/R490W genotype, mRNA carrying frameshift mutation 550 delA was not detected, probably due to its degradation by nonsense-mediated mRNA decay. In muscle biopsies of two LGMD2A patients, a neurogenic pattern simulating a neurogenic lesion was observed. Immunoblot analysis revealed the deficiency of p 94 in all genetically confirmed cases of LGMD2A, and secondary dysferlin deficiency was demonstrated on muscle membranes in 6 patients using immunofluorescence. Thus, we find a combination of DNA and mRNA mutational analysis to be useful in the diagnosis of LGMD2A. Moreover, our study expands the spectrum of calpainopathies to cases that simulate a neurogenic lesion in muscle biopsies, and the knowledge of possible secondary deficiencies of muscular proteins also contributes to a diagnosis of LGMD2A.
authors.affiliation: Department of Pathology, University Hospital Brno, Jihlavská 20, 625 00, Brno, Czech Republic. marherman@post.cz
authors.forename: Markéta
authors.initials: M
authors.lastname: Hermanová
authors.forename: Eva
authors.initials: E
authors.lastname: Zapletalová
authors.forename: Jana
authors.initials: J
authors.lastname: Sedlácková
authors.forename: Tána
authors.initials: T
authors.lastname: Chrobáková
authors.forename: Ondrej
authors.initials: O
authors.lastname: Letocha
authors.forename: Iva
authors.initials: I
authors.lastname: Kroupová
authors.forename: Josef
authors.initials: J
authors.lastname: Zámecník
authors.forename: Petr
authors.initials: P
authors.lastname: Vondrácek
authors.forename: Radim
authors.initials: R
authors.lastname: Mazanec
authors.forename: Tatána
authors.initials: T
authors.lastname: Maríková
authors.forename: Stanislav
authors.initials: S
authors.lastname: Vohánka
authors.forename: Lenka
authors.initials: L
authors.lastname: Fajkusová
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D002154:Calpain / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D018153:Czech Republic; D004252:DNA Mutational Analysis; D000073939:Dysferlin; D005260:Female; D005455:Fluorescent Antibody Technique; D005838:Genotype; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism; D008875:Middle Aged; D009124:Muscle Proteins / Q000276:immunology / Q000378:metabolism; D018482:Muscle, Skeletal / Q000473:pathology; D049288:Muscular Dystrophies, Limb-Girdle / Q000235:genetics* / Q000473:pathology*; D009243:NAD / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C114839:DYSF protein, human; D000073939:Dysferlin; D007527:Isoenzymes; D008565:Membrane Proteins; D009124:Muscle Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D009243:NAD; C105884:CAPN3 protein, human; D002154:Calpain