Browsing by Author "Vilarinho, Laura"
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- Assessing Lysosomal Disorders in the NGS Era: Identification of Novel Rare VariantsPublication . Encarnação, Marisa; Coutinho, Maria Francisca; Silva, Lisbeth; Ribeiro, Diogo; Ouesleti, Souad; Campos, Teresa; Santos, Helena; Martins, Esmeralda; Cardoso, Maria Teresa; Vilarinho, Laura; Alves, SandraLysosomal storage diseases (LSDs) are a heterogeneous group of genetic disorders with variable degrees of severity and a broad phenotypic spectrum, which may overlap with a number of other conditions. While individually rare, as a group LSDs affect a significant number of patients, placing an important burden on affected individuals and their families but also on national health care systems worldwide. Here, we present our results on the use of an in-house customized next-generation sequencing (NGS) panel of genes related to lysosome function as a first-line molecular test for the diagnosis of LSDs. Ultimately, our goal is to provide a fast and effective tool to screen for virtually all LSDs in a single run, thus contributing to decrease the diagnostic odyssey, accelerating the time to diagnosis. Our study enrolled a group of 23 patients with variable degrees of clinical and/or biochemical suspicion of LSD. Briefly, NGS analysis data workflow, followed by segregation analysis allowed the characterization of approximately 41% of the analyzed patients and the identification of 10 different pathogenic variants, underlying nine LSDs. Importantly, four of those variants were novel, and, when applicable, their effect over protein structure was evaluated through in silico analysis. One of the novel pathogenic variants was identified in the GM2A gene, which is associated with an ultra-rare (or misdiagnosed) LSD, the AB variant of GM2 Gangliosidosis. Overall, this case series highlights not only the major advantages of NGS-based diagnostic approaches but also, to some extent, its limitations ultimately promoting a reflection on the role of targeted panels as a primary tool for the prompt characterization of LSD patients.
- Coarse face, hypotonia, and neurodevelopmental regressionPublication . Miranda, Ana Margalha; Ezequiel, Marta; Luís, Catarina; Dupont, Juliette; Gaspar, Paulo; Vilarinho, Laura; Janeiro, Patrícia; Gaspar, AnaInborn errors of metabolism are a heterogeneous class of multisystemic diseases which, although individually rare, are collectively quite common. Central nervous system is usually affected. The authors report the case of a five-month-old girl, daughter of non-consanguineous parents, born after an unremarkable full-term pregnancy and delivery. Hypotonia and neurodevelopmental regression were noted from the age of five months, along with progressive onset of facial dysmorphism, hepatomegaly, seizures, and dilated cardiomyopathy. Gangliosidosis type 1 diagnosis was confirmed by biochemical, enzymatic, and genetic findings. This report enhances the relevance of multidisciplinary approach and follow-up.
- Leigh Syndrome Spectrum: A Portuguese Population Cohort in an Evolutionary Genetic EraPublication . Baldo, Manuela Schubert; Nogueira, Célia; Pereira, Cristina; Janeiro, Patrícia; Ferreira, Sara; Lourenço, Charles M.; Bandeira, Anabela; Martins, Esmeralda; Magalhães, Marina; Rodrigues, Esmeralda; Santos, Helena; Ferreira, Ana Cristina; Vilarinho, LauraMitochondrial diseases are the most common inherited inborn error of metabolism resulting in deficient ATP generation, due to failure in homeostasis and proper bioenergetics. The most frequent mitochondrial disease manifestation in children is Leigh syndrome (LS), encompassing clinical, neuroradiological, biochemical, and molecular features. It typically affects infants but occurs anytime in life. Considering recent updates, LS clinical presentation has been stretched, and is now named LS spectrum (LSS), including classical LS and Leigh-like presentations. Apart from clinical diagnosis challenges, the molecular characterization also progressed from Sanger techniques to NGS (next-generation sequencing), encompassing analysis of nuclear (nDNA) and mitochondrial DNA (mtDNA). This upgrade resumed steps and favored diagnosis. Hereby, our paper presents molecular and clinical data on a Portuguese cohort of 40 positive cases of LSS. A total of 28 patients presented mutation in mtDNA and 12 in nDNA, with novel mutations identified in a heterogeneous group of genes. The present results contribute to the better knowledge of the molecular basis of LS and expand the clinical spectrum associated with this syndrome.
- NPC1 silent variant induces skipping of exon 11 (p.V562V) and unfolded protein response was found in a specific Niemann‐Pick type C patientPublication . Encarnação, Marisa; Coutinho, Maria Francisca; Cho, Soo Min; Cardoso, Maria Teresa; Ribeiro, Isaura; Chaves, Paulo; Santos, Juliana Inês; Quelhas, D; Lacerda, Lucia; Leão Teles, Elisa; Futerman, Anthony H.; Vilarinho, Laura; Alves, SandraBackground: Niemann-Pick type C (NPC, MIM #257220) is a neuro-visceral disease, caused predominantly by pathogenic variants in the NPC1 gene. Here we studied patients with clinical diagnosis of NPC but inconclusive results regarding the molecular analysis. Methods: We used a Next-Generation Sequencing (NGS)-panel followed by cDNA analysis. Latter, we used massively parallel single-cell RNA-seq (MARS-Seq) to address gene profiling changes and finally the effect of different variants on the protein and cellular levels. Results: We identified novel variants and cDNA analysis allowed us to establish the functional effect of a silent variant, previously reported as a polymorphism. We demonstrated that this variant induces the skipping of exon 11 leading to a premature stop codon and identified it in NPC patients from two unrelated families. MARS-Seq analysis showed that a number of upregulated genes were related to the unfolded protein response (UPR) and endoplasmic reticulum (ER) stress in one specific patient. Also, for all analyzed variants, the NPC1 protein was partially retained in the ER. Conclusion: We showed that the NPC1 silent polymorphism (p.V562V) is a disease-causing variant in NPC and that the UPR is upregulated in an NPC patient.
- Suspecting classical homocystinuria in an adolescent born before the newborn screening programPublication . Carvalho, Fábia; Campos, Teresa; Reis, Joana; Portela, Mariana; Vasconcelos, Carla; Ferreira, Carla; Cerqueira, Arnaldo; Oliveira, Ângela; Vilarinho, Laura; Leão-Teles, Elisa; Rodrigues, EsmeraldaIntroduction: Classical homocystinuria (HCU) is an autosomal recessive disorder caused by a deficiency in the cystathionine beta-synthase enzyme and associated with a high probability of vascular complications. Herein is presented the case of an adolescent diagnosed with HCU during cerebral venous sinus thrombosis (CVST) study. Case Report: A 14-year-old girl presented with thrombophilia screening tests suggestive of HCU during CVST study. After referral to an Inherited Metabolic Diseases Unit, she started supplementation with pyridoxine, folic acid, vitamin B12, betaine anhydrous, and cysteine and was advised to restrict natural proteins and methionine from diet. Genetic analysis revealed a homozygous CBS mutation (c.572C>T (p.T191M) with c.699C>T (p.Y233Y) polymorphism. Discussion: In adolescents born before 2004 (year of implementation of the Portuguese newborn screening program), HCU should be considered when studying hypercoagulability syndromes, as it is a treatable condition and treatment can prevent major morbidity and mortality causes.
- TYROSINEMIA TYPE III: A CASE REPORT OF SIBLINGS AND LITERATURE REVIEWPublication . Barroso, Fábio; Correia, Joana; Bandeira, Anabela; Carmona, Carla; Vilarinho, Laura; MF, Almeida; Rocha, Júlio César; Martins, EsmeraldaObjective: Tyrosinemia type III (HT III) is the rarest form of tyrosinemia, and the full clinical spectrum of this disorder is still unknown. The neurological involvement varies, including intellectual impairment and attention deficit disorder with hyperactivity (ADHD). We report the case of two siblings diagnosed with HT III at different ages. Case description: The index case was diagnosed by newborn screening for endocrine and metabolic disorders, starting a low-protein diet immediately, with a consistent decrease in tyrosine levels. By the age of three, the child displayed a hyperactive behavior, starting treatment for ADHD two years later. At seven years of age, he shows a slight improvement in terms of behavior and attention span and has a cognitive performance slightly lower than his peers, despite maintaining acceptable tyrosine levels. His sister, who had a history of ADHD since age five, was diagnosed with HT III after family screening at the age of eight. Despite initiating a dietetic treatment, her behavior did not improve, and she has a mild intellectual impairment. Comments: This is the first case report describing siblings with HT III who underwent nutritional treatment with a low-protein diet in different phases of life, with a better neurological and behavioral evaluation in the patient who started treatment earlier.