Loading...
8 results
Search Results
Now showing 1 - 8 of 8
- Usher syndrome and Nebulin‐associated myopathy in a single patient due to variants in MYO7A and NEBPublication . Maia, N; Soares, Ana Rita; Fortuna, Ana; Marques, Isabel; Gonçalves, Ana; Santos, Rosário; Pires, Manuel; De Brouwer, Arjan; Jorge, PaulaIn a patient with Usher syndrome and atypical muscle complaints, we have identified two separate variants in MYO7A andNEB genes by exome sequencing. The homozygous variants in these two recessive genes could explain the full phenotype of our patient.
- Desenvolvimento neurocognitivo em 99 adolescentes e adultos com fenilcetonúria: ganhos em saúde resultantes de uma abordagem multidisciplinarPublication . Carmona, C.M.; Almeida, M.F.; Rocha, J.C.; Soares, G.; Fortuna, A.
- Unraveling the pathogenesis of ARX polyalanine tract variants using a clinical and molecular interfacing approachPublication . Marques, I.; Sá, J.; Soares, G.; Mota, M.; Pinheiro, C.; Aguiar, L.; Amado, M.; Soares, C.; Calado, A.; Dias, P.; Sousa, A.; Fortuna, A.; Santos, R.; Howell, K.; Ryan, M.; Leventer, R.; Sachdev, R.; Catford, R.; Friend, K; Mattiske, T.; Shoubridge, C.; Jorge, P.The Aristaless-related homeobox (ARX) gene is implicated in intellectual disability with the most frequent pathogenic mutations leading to expansions of the first two polyalanine tracts. Here, we describe analysis of the ARX gene outlining the approaches in the Australian and Portuguese setting, using an integrated clinical and molecular strategy. We report variants in the ARX gene detected in 19 patients belonging to 17 families. Seven pathogenic variants, being expansion mutations in both polyalanine tract 1 and tract 2, were identifyed, including a novel mutation in polyalanine tract 1 that expands the first tract to 20 alanines. This precise number of alanines is sufficient to cause pathogenicity when expanded in polyalanine tract 2. Five cases presented a probably non-pathogenic variant, including the novel HGVS: c.441_455del, classified as unlikely disease causing, consistent with reports that suggest that in frame deletions in polyalanine stretches of ARX rarely cause intellectual disability. In addition, we identified five cases with a variant of unclear pathogenic significance. Owing to the inconsistent ARX variants description, publications were reviewed and ARX variant classifications were standardized and detailed unambiguously according to recommendations of the Human Genome Variation Society. In the absence of a pathognomonic clinical feature, we propose that molecular analysis of the ARX gene should be included in routine diagnostic practice in individuals with either nonsyndromic or syndromic intellectual disability. A definitive diagnosis of ARX-related disorders is crucial for an adequate clinical follow-up and accurate genetic counseling of at-risk family members.
- Diagnóstico e benefícios para a comunidade na doença genética: contributo da citogenéticaPublication . Oliva-Teles, N.; Freitas, M.; Lopes, E.; Aguiar, J.; Marques, B.; Fortuna, A.; Silva, M.
- Arx-related disorders: several distinct phenotypes, one mutated genePublication . Sá, M.J.; Soares, G.; Silva, J.; Fortuna, A.; Santos, R.; Marques, I.; Jorge, P.
- Hyperinsulinaemic Hypoglycaemia and Polycystic Kidney Disease – A Rare Case Concerning PMM2 Gene PleiotropyPublication . Borges, Teresa; Fortuna, Ana; Faria, Maria Do Sameiro; Oliveira, Maria João; Freitas, Joana; Santos Silva, Ermelinda; Quelhas, D; Figueiredo, Catarina Matos; Soares, Ana RitaCo-occurrence of hyperinsulinaemic hypoglycaemia and polycystic kidney disease (HIPKD) has been recently described. It is caused by a non-coding variant in the promoter region for phosphomannomutase 2 (PMM2), c.-167G>T, both in homozygous or compound heterozygous variants with deleterious coding. Although PMM2 has been associated with congenital disorder of glycosylation, patients do not present with this phenotype and have normal carbohydrate-deficient transferring testing. The authors present a rare case where specific PMM2 study was performed as a result of clinical suspicions. The patient was a 6-year-old female followed at our clinic due to congenital hyperinsulinism since she was 1 month old. She also presented with bilateral polycystic kidneys, detected in prenatal set, and simple hepatic cysts, for which she was treated with diazoxide and captopril. Initial metabolic and genetic studies were normal. PMM2 gene sequence study revealed the promotor variant c.-167G>T in compound heterozygosity with the previously described pathogenic variant c.422G>A (p.Arg141His), confirming the diagnosis of HIPKD. This is a notable case as it highlights the importance of keeping this diagnostic hypothesis in mind and serves as a reminder to perform proper clinical and genetic investigation. A correct, and early, diagnosis will avoid unnecessary additional investigations and will allow appropriate genetic counselling for this autosomal recessive disorder.
- A 26-Year Experience in Chorionic Villus Sampling Prenatal Genetic DiagnosisPublication . Jorge, P.; Mota-Freitas, M.; Santos, R.; Silva, M.; Soares, G.; Fortuna, A.Abstract: This report describes the trends of chorionic villus sampling (CVS) referred for prenatal genetic diagnosis in the past two and a half decades in a Portuguese Center. Our cohort of 491 CVS was mostly performed by the transcervical method at the 12th gestational week. Data collected within the framework of this study relate to the following: sampling method, referral reason versus abnormality and incidence of procedure-related pregnancy loss, that declined to about 0.5% over the last 15 years. The year 2000 represented a change in referral reasons for chorionic tissue collection, shifting from almost exclusively for cytogenetic testing to an increasing number of molecular tests for monogenic disorders. Herein, success rates as well as cytogenetic and/or molecular DNA results are presented. These latter include not only tests for several monogenic disorders, but also aneuploidy and maternal cell contamination screening. This retrospective analysis reiterates that CVS is a safe and reliable first trimester technique for prenatal diagnosis in high genetic risk pregnancies.
- Infantile Refsum Disease: Influence of Dietary Treatment on Plasma Phytanic Acid LevelsPublication . Sá, M.; Rocha, J.; Almeida, M.; Carmona, C.; Martins, E.; Miranda, V.; Coutinho, M.; Ferreira, R.; Pacheco, S.; Laranjeira, F.; Ribeiro, I.; Fortuna, A.; Lacerda, L.Infantile Refsum disease (IRD) is one of the less severe of Zellweger spectrum disorders (ZSDs), a group of peroxisomal biogenesis disorders resulting from a generalized peroxisomal function impairment. Increased plasma levels of very long chain fatty acids (VLCFA) and phytanic acid are biomarkers used in IRD diagnosis. Furthermore, an increased plasma level of phytanic acid is known to be associated with neurologic damage. Treatment of IRD is symptomatic and multidisciplinary.The authors report a 3-year-old child, born from consanguineous parents, who presented with developmental delay, retinitis pigmentosa, sensorineural deafness and craniofacial dysmorphisms. While the relative level of plasma C26:0 was slightly increased, other VLCFA were normal. Thus, a detailed characterization of the phenotype was essential to point to a ZSD. Repeatedly increased levels of plasma VLCFA, along with phytanic acid and pristanic acid, deficient dihydroxyacetone phosphate acyltransferase activity in fibroblasts and identification of the homozygous pathogenic mutation c.2528G>A (p.Gly843Asp) in the PEX1 gene, confirmed this diagnosis. Nutritional advice and follow-up was proposed aiming phytanic acid dietary intake reduction. During dietary treatment, plasma levels of phytanic acid decreased to normal, and the patient's development evaluation showed slow progressive acquisition of new competences.This case report highlights the relevance of considering a ZSD in any child with developmental delay who manifests hearing and visual impairment and of performing a systematic biochemical investigation, when plasma VLCFA are mildly increased. During dietary intervention, a biochemical improvement was observed, and the long-term clinical effect of this approach needs to be evaluated.