Browsing by Author "Barbot, C"
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- Clinical and Molecular Findings in Four New Patients Harbouring the mtDNA 8993T C MutationPublication . Vilarinho, L; Carrozzo, R; Barbot, C; Calado, E; Tessa, A; Dionisi-Vici, C; Guimarães, A; Santorelli, FM
- LAMA2 Gene Analysis in a Cohort of 26 Congenital Muscular Dystrophy PatientsPublication . Oliveira, J; Santos, R; Soares-Silva, I; Jorge, P; Vieira, E; Oliveira, ME; Moreira, A; Coelho, T; Ferreira, JC; Fonseca, MJ; Barbosa, C; Prats, J; Aríztegui, ML; Martins, ML; Moreno, T; Heinimann, K; Barbot, C; Pascual-Pascual, SI; Cabral, A; Fineza, I; Santos, M; Bronze-da-Rocha, ECongenital muscular dystrophy type 1A (MDC1A) is caused by mutations in the LAMA2 gene encoding laminin-alpha2. We describe the molecular study of 26 patients with clinical presentation, magnetic resonance imaging and/or laminin-alpha2 expression in muscle, compatible with MDC1A. The combination of full genomic sequencing and complementary DNA analysis led to the particularly high mutation detection rate of 96% (50/52 disease alleles). Besides 22 undocumented polymorphisms, 18 different mutations were identified in the course of this work, 14 of which were novel. In particular, we describe the first fully characterized gross deletion in the LAMA2 gene, encompassing exon 56 (c.7750-1713_7899-2153del), detected in 31% of the patients. The only two missense mutations detected were found in heterozygosity with nonsense or truncating mutations in the two patients with the milder clinical presentation and a partial reduction in muscle laminin-alpha2. Our results corroborate the previous few genotype/phenotype correlations in MDC1A and illustrate the importance of screening for gross rearrangements in the LAMA2 gene, which may be underestimated in the literature.
- Rett Syndrome With and Without Detected MECP2 Mutations: an Attempt to Redefine PhenotypesPublication . Temudo, T; Santos, M; Ramos, E; Dias, K; Vieira, JP; Moreira, A; Calado, E; Carrilho, I; Oliveira, G; Levy, A; Barbot, C; Fonseca, M; Cabral, A; Cabral, P; Monteiro, J; Borges, L; Gomes, R; Mira, G; Pereira, SA; Santos, M; Fernandes, A; Epplen, JT; Sequeiros, J; Maciel, PBackground: The diagnosis of Rett syndrome (RTT) is based on a set of clinical criteria, irrespective of mutation status. The aims of this study were (1) to define the clinical differences existing between patients with Rett syndrome with (Group I) and without a MECP2 mutation (Group II), and (2) to characterize the phenotypes associated with the more common MECP2 mutations. Patients and Methods: We analyzed 87 patients fulfilling the clinical criteria for RTT. All were observed and videotaped by the same paediatric neurologist. Seven common mutations were considered separately, and associated clinical features analysed. Results: Comparing Group I and II, we found differences concerning psychomotor development prior to onset, acquisition of propositive manipulation and language, and evolving autistic traits. Based on age at observation, we found differences in eye pointing, microcephaly, growth, number of stereotypies, rigidity, ataxia and ataxic-rigid gait, and severity score. Patients with truncating differed from those with missense mutations regarding acquisition of propositive words and independent gait, before the beginning of the disease, and microcephaly, growth, foot length, dystonia, rigidity and severity score, at the time of observation. Patients with the R168X mutation had a more severe phenotype, whereas those with R133C showed a less severe one. Patients with R294X had a hyperactive behaviour, and those with T158M seemed to be particularly ataxic and rigid. Conclusion: A clear regressive period (with loss of prehension and language, deceleration of growth) and the presence of more than three different stereotypies, rigidity and ataxic-rigid gait seemed to be very helpful in differentiating Group I from Group II.