Browsing by Author "Fortuna, AM"
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- Clinical and Molecular Characterization of Diastrophic Dysplasia in the Portuguese PopulationPublication . Barbosa, M; Sousa, AB; Medeira, A; Lourenço, T; Saraiva, J; Pinto-Basto, J; Soares, G; Fortuna, AM; Superti-Furga, A; Mittaz, L; Reis-Lima, M; Bonafé, LSLC26A2-related dysplasias encompass a spectrum of diseases: from lethal achondrogenesis type 1B (ACG1B; MIM #600972) and atelosteogenesis type 2 (AO2; MIM #256050) to classical diastrophic dysplasia (cDTD; MIM #222600) and recessive multiple epiphyseal dysplasia (rMED; MIM #226900). This study aimed at characterizing clinically, radiologically and molecularly 14 patients affected by non-lethal SLC26A2-related dysplasias and at evaluating genotype-phenotype correlation. Phenotypically, eight patients were classified as cDTD, four patients as rMED and two patients had an intermediate phenotype (mild DTD - mDTD, previously 'DTD variant'). The Arg279Trp mutation was present in all patients, either in homozygosity (resulting in rMED) or in compound heterozygosity with the known severe alleles Arg178Ter or Asn425Asp (resulting in DTD) or with the mutation c.727-1G>C (causing mDTD). The 'Finnish mutation', c.-26+2T>C, and the p.Cys653Ser, both frequent mutations in non-Portuguese populations, were not identified in any of the patients of our cohort and are probably very rare in the Portuguese population. A targeted mutation analysis for p.Arg279Trp and p.Arg178Ter in the Portuguese population allows the identification of approximately 90% of the pathogenic alleles.
- Congenital Disorders of Glycosylation in Portugal—Two Decades of ExperiencePublication . Quelhas, D; Martins, E; Azevedo, L; Bandeira, A; Diogo, L; Garcia, P; Sequeira, S; Ferreira, AC; Teles, EL; Rodrigues, E; Fortuna, AM; Mendonça, C; Fernandes, HC; Medeira, A; Gaspar, A; Janeiro, P; Oliveira, A; Laranjeira, F; Ribeiro, I; Souche, E; Race, V; Keldermans, L; Matthijs, G; Jaeken, JObjective: To describe the clinical, biochemical, and genetic features of both new and previously reported patients with congenital disorders of glycosylation (CDGs) diagnosed in Portugal over the last 20 years. Study design: The cohort includes patients with an unexplained multisystem or single organ involvement, with or without psychomotor disability. Serum sialotransferrin isoforms and, whenever necessary, apolipoprotein CIII isoforms and glycan structures were analyzed. Additional studies included measurement of phosphomannomutase (PMM) activity and analysis of lipid-linked oligosaccharides in fibroblasts. Sanger sequencing and massive parallel sequencing were used to identify causal variants or the affected gene, respectively. Results: Sixty-three individuals were diagnosed covering 14 distinct CDGs; 43 patients diagnosed postnatally revealed a type 1, 14 a type 2, and 2 a normal pattern on serum transferrin isoelectrofocusing. The latter patients were identified by whole exome sequencing. Nine of them presented also a hypoglycosylation pattern on apolipoprotein CIII isoelectrofocusing, pointing to an associated O-glycosylation defect. Most of the patients (62%) are PMM2-CDG and the remaining carry pathogenic variants in ALG1, ATP6AP1, ATP6AP2, ATP6V0A2, CCDC115, COG1, COG4, DPAGT1, MAN1B1, SLC35A2, SRD5A3, RFT1, or PGM1. Conclusions: Portuguese patients with CDGs are presented in this report, some of them showing unique clinical phenotypes. Among the 14 genes mutated in Portuguese individuals, 8 are shared with a previously reported Spanish cohort. However, regarding the mutational spectrum of PMM2-CDG, the most frequent CDG, a striking similarity between the 2 populations was found, as only 1 mutated allele found in the Portuguese group has not been reported in Spain.