Browsing by Author "Bronze-da-Rocha, Elsa"
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- Anoctamin 5: A New Candidate Gene For Portuguese Patients With Adult Onset Limb-Girdle Muscular DystrophyPublication . Santos, Rosário; Vieira, Emília; Moutinho, Ariana; Oliveira, Jorge; Negrão, Luís; Bronze-da-Rocha, ElsaIntroduction: The limb-girdle muscular dystrophies (LGMDs) show wide genetic and clinical heterogeneity. Recessive mutations in the ANO5 gene, which encodes a putative calcium-activated chloride channel of the anoctamin family, have been recently identified in families with LGMD type 2L and non-dysferlin distal muscular dystrophy (MMD3). The LGMD2L phenotype is characterized by proximal weakness, with prominent asymmetrical quadriceps femoris and biceps brachii atrophy, whereas MMD3 is associated with distal weakness, particularly of calf muscles. Methods: In a group of 125 patients with clinical LGMD, but no mutations in other candidate genes involved in LGMD, we screened the “common” mutation c.191dupA. Subsequently, in 10 selected patients the entire coding region of ANO5 was fully sequenced. Results: Mutations were identified in 4 patients (3 families), all presenting hyperCKemia and adult onset proximal lower limb weakness. The common mutation c.191dupA was found in one family (2 patients), in a homozygous state. This mutation results in a frameshift with a consequent premature stop codon (p.Asn64LysfsX15), triggering nonsense-mediated mRNA decay. A novel substitution identified in exon 18 (c.2012A>G), predictably a missense mutation, was shown to in fact create a new donor splice site. mRNA studies confirmed aberrant splicing in exon 18, promoting an in-frame deletion of 18 nucleotides (r.2012_2029del) that results in a truncated protein (p.Tyr671_Val677delinsPhe). The third patient had a heterozygous nucleotide substitution in exon 8, c.692G>T, predicted to result in a missense mutation (p.Gly231Val). The Gly231 residue, localized in the N-terminal domain, is evolutionarily conserved. In this patient the second mutation has not yet been identified. Conclusion: Although c.191dupA was detected in only 1/125 patients, systematic sequencing of ANO5 in 10 patients revealed a further two positive cases, indicating that the anoctaminopathies may account for a reasonable number of our LGMD patients.
- 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.
- Migration of an ancestral dysferlin splicing mutation from the Iberian peninsula to South AmericaPublication . Vernengo, Luis; Oliveira, Jorge; Krahn, Martin; Vieira, Emília; Santos, Rosário; Carraso, Luisa; Negrão, Luis; Panuncio, Ana; Leturcq, France; Labelle, Veronique; Bronze-da-Rocha, Elsa; Mesa, Rosario; Pizzarossa, Carlos; Lévy, Nicolas; Rodrigues, Maria-MirtaMiyoshi myopathy, LGMD2B and DMAT are primary dysferlinopathies that belong to a group of muscular dystrophies inherited in an autosomal recessive mode. Additional presentations range from isolated hyperCKemia to severe functional disability. LGMD2B involves predominantly the proximal muscles of the lower limbs whereas in Miyoshi myopathy the muscles involved are those of the posterior muscle compartment of the calf. DMAT is characterized by anterior tibial muscle weakness which rapidly progresses to the lower and upper proximal muscles. Onset is usually in young adults, but congenital and late-onset forms have also been reported. We present the first Uruguayan patient to have been diagnosed with Miyoshi myopathy and four Portuguese patients that carry a novel mutation in exon12/intron12 boundary: c.1180_1180 + 7delAGTGCGTG (r.1054_1284del) in the DYSF gene. Evidence of a founder effect due to a common ancestral origin of this mutation was detected in heterozygosity in four patients and in homozygosity in one patient. The homozygous patient has no proven inbreeding so it can be inferred that the mutation is identical by descent. All patients shared a common haplotypes block identical in state between markers Cy172-H32 and D2S211. We believe that it derives from a common mutational event which is ancestral because of the recombination between the mutated gene and the telomeric flanking marker D2S2113. As this haplotype is not common among the Portuguese population, it is very unlikely that these mutated DYSF alleles represent recurrent events. This is the sixth founder effect of the DYSF gene to be found in the world so far.
- Molecular profile of 307 Portuguese patients with dystrophinopathy, including thirty-nine new variantsPublication . Gonçalves, Ana Rita; Santos, Rosário; Vieira, Emília; Vieira, José Pedro; Fineza, Isabel; Moreno, Teresa; Santos, Manuela; Bronze-da-Rocha, ElsaMutations in the dystrophin gene (DMD) give rise to the allelic Duchenne or Becker muscular dystrophies. Besides providing a differential diagnosis for adequate clinical follow-up and management, the molecular characterization of these patients is becoming increasingly important in light of the recent and promising mutation-based therapeutic approaches. Due to the size and complexity of DMD, as well as the diversity of mutation types, molecular analysis requires a combination of techniques that enable the detection of gross deletions, duplications and the more subtle point mutations. In the course of our diagnostic service provided on a national basis, a total of 307 patients, representing 282 unrelated families, have been characterized at the molecular level. We identified 174 different mutations, where the distribution according to type was found to be in agreement with that reported in the literature for large cohorts. Also as expected, approximately 1/3 of the cases were shown to be de novo occurrences, as ascertained among the “sporadic” cases (25/82). These neo-mutations were comprised by 18% deletions, 6% duplications and 6% point mutations. We describe a total of thirty-nine undocumented variants, three of which were detected in obligate carrier female relatives of deceased patients. These new variants include 9 gross deletions, 8 gross duplications and 22 smaller mutations (deletions, duplications, delins rearrangements and nonsense or splice-site substitutions). Comprehensive analysis often involved expression studies at the mRNA level to help delineate breakpoint junctions, to identify altered splicing and ultimately to provide an explanation for apparent exceptions to the reading frame rule. This detailed molecular characterization is also important for the purpose of including our patients in the DMD National Registry, which will be articulated with the TREAT-NMD Global Database
- Novel ancestral Dysferlin splicing mutation which migrated from the Iberian peninsula to South AmericaPublication . Vernengo, Luis; Oliveira, Jorge; Krahn, Martin; Vieira, Emília; Santos, Rosário; Carrasco, Luisa; Negrão, Luis; Panuncio, Ana; Leturcq, France; Labelle, Veronique; Bronze-da-Rocha, Elsa; Mesa, Rosário; Pizzarossa, Carlos; Lévy, Nicolas; Rodriguez, Maria-MirtaPrimary dysferlinopathies are a group of recessive heterogeneous muscular dystrophies. The most common clinical presentations are Miyoshi myopathy and LGMD2B. Additional presentations range from isolated hyperCKemia to severe functional disability. Symptomatology begins in the posterior muscle compartment of the calf and its clinical course progresses slowly in Miyoshi myopathy whereas LGMD2B involves predominantly the proximal muscles of the lower limbs. The age of onset ranges from 13 to 60 years in Caucasians. We present five patients that carry a novel mutation in the exon12/intron12 boundary: c.1180_1180 + 7delAGTGCGTG (r.1054_1284del). We provide evidence of a founder effect due to a common ancestral origin of this mutation, detected in heterozygosity in four patients and in homozygosity in one patient.
- Prediction of deleterious nsSNPs in human UGT1A1 gene by web available algorithm toolsPublication . Rodrigues, Carina; Costa, Elísio; Vieira, Emília; Santos, Rosário; Santos-Silva, Alice; Bronze-da-Rocha, Elsa
- 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.
- UGT1A1 gene variations in individuals with and without clinical diagnosis of Gilbert SyndromePublication . Rodrigues, Carina; Vieira, Emília; de Carvalho, João; Costa, Elísio; Santos, Rosário; Santos-Silva, Alice; Bronze-da-Rocha, Elsa
- Variação Inter-Individual nos Níveis de Bilirrubina: O papel de Factores Genéticos e AdquiridosPublication . Rodrigues, Carina; Vieira, Emília; Santos, Rosário; de Carvalho, João; Santos-Silva, Alice; Costa, Elísio; Bronze-da-Rocha, Elsa
- Variação Inter-Individual nos Níveis de Bilirrubina: O papel de Factores Genéticos e AdquiridosPublication . Rodrigues, Carina; Vieira, Emília; Santos, Rosário; de Carvalho, João; Santos-Silva, Alice; Costa, Elísio; Bronze-da-Rocha, Elsa