Browsing by Author "Geraldo, Argemiro"
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- Distrofias Musculares das Cinturas autossómicas recessivas diagnosticadas nos Hospitais da Universidade de CoimbraPublication . Negrão, Luis; Geraldo, Argemiro; Rebelo, Olinda; Matos, Anabela; Santos, Rosário; Bronze-da-Rocha, ElsaIntroduction Limb-girdle muscular dystrophies (LGMDs) are a hetero¬geneous group of muscle diseases. Autosomal dominant (LGMD1) and recessive (LGMD2) forms are recognized, each one with several subtypes. In Portugal there are no studies reporting the relative distribution of the different subtypes of LGMD2. Objective To determine the subtypes of LGMD2 diagnosed and their relative distribution at the Neurology Department of the Coimbra University Hospital. Material and Methods The medical files of the patients with a diagnosis of LGMD2 were analysed and individual clinical, laboratory, pathologic and molecular data were recorded. The time frame of analysis was from 2000 to 2010. Results Forty-two patients from thirty-nine unrelated families were identified with a LGMD2 diagnosis. There were twenty-three female and nineteen male patients. Parental consan¬guinity was reported in eighteen patients (fifteen families). Their actual mean age is 44.6 years and the mean age of first symptoms was 23.2 years. The mean time from first symptoms to genetic diagnosis was 16.2 years. Twenty patients are wheel¬chair bound and seventeen can't raise the arms above the shoulder level. Three patients presented symptomatic dilated cardiomyopathy and twelve patients a restrictive respiratory syndrome, which was severe in five. The mean CK value was elevated in all LGMD2 subtypes. Immunohistochemistry sug¬gested the specific diagnosis in twenty patients (LGMD2B: 11; LGMD2C-F: 9). Molecular studies performed in forty-one patients revealed 27 homozygous mutations, 11 compound heterozygous mutations and 3 heterozygous mutations. The LGMD2 subtypes diagnosed and the number of patients of each subtype was: LGMD2A: 5, LGMD2B: 16, LGMD2C-F: 9 (one patient without molecular study), LGMD2G: I, LGMD2I: 7, LGMD2J: 1. LGMD2L: 3. Conclusion This retrospective analysis shows that most of the autoso¬mal recessive LGMDs subtypes are represented in Portugal, being the LGMD2B subtype the most frequente. Rarer sub¬types, like LGMD2G and J, were also found rare.
- Private dysferlin exon skipping mutation (c.5492G>A) with a founder effect reveals further alternative splicing involving exons 49-51Publication . Santos, Rosário; Oliveira, Jorge; Vieira, Emília; Coelho, Teresa; Carneiro, António Leite; Evangelista, Teresinha; Dias, Cristina; Fortuna, Ana; Geraldo, Argemiro; Negrão, Luís; Guimarães, António; Bronze-da-Rocha, ElsaThe allelic muscle disorders known as limb-girdle muscular dystrophy type 2B (LGMD2B), Miyoshi myopathy and distal anterior compartment myopathy result from defects in dysferlin—a sarcolemma-associated protein involved in membrane repair. Mutation screening in the dysferlin gene (DYSF) enabled the identification of seven Portuguese patients presenting the variant c.5492G4A, which was observed to promote skipping of exon 49 (p.Gly1802ValfsX17). Several residually expressed products of alternative splicing also involving exons 50 and 51 were detected in the leukocytes and muscle of both patients and normal controls. Quantitative transcript analysis confirmed these results and revealed that D49/D50 transcripts were predominant in blood. Although the patients were apparently unrelated, the c.5492G4A mutation was found in linkage disequilibrium with a particularly rare haplotype in the population, corroborating the hypothesis of a common origin. Despite the presence of the same mutation on the same haplotype background, onset of the disease was heterogeneous, with either proximal or distal muscle involvement.