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Clínica de Patologia e Genética - Artigos publicados em revistas indexadas na Pubmed/Medline

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  • Should patients with Phosphomannomutase 2-CDG (PMM2-CDG) be screened for adrenal insufficiency?
    Publication . Čechová, Anna; Honzík, Tomáš; Edmondson, Andrew C.; Ficicioglu, Can; Serrano, Mercedes; Barone, Rita; De Lonlay, Pascale; Schiff, Manuel; Witters, Peter; Lam, Christina; Patterson, Marc; Janssen, Mirian C.H.; Correia, Joana; Quelhas, D; Sykut-Cegielska, Jolanta; Plotkin, Horacio; Morava, Eva; Sarafoglou, Kyriakie
    PMM2-CDG is the most common congenital disorder of glycosylation (CDG) accounting for almost 65% of known CDG cases affecting N-glycosylation. Abnormalities in N-glycosylation could have a negative impact on many endocrine axes. There is very little known on the effect of impaired N-glycosylation on the hypothalamic-pituitary-adrenal axis function and whether CDG patients are at risk of secondary adrenal insufficiency and decreased adrenal cortisol production. Cortisol and ACTH concentrations were simultaneously measured between 7:44 am to 1 pm in forty-three subjects (20 female, median age 12.8 years, range 0.1 to 48.6 years) participating in an ongoing international, multi-center Natural History study for PMM2-CDG (ClinicalTrials.gov Identifier: NCT03173300). Of the 43 subjects, 11 (25.6%) had cortisol below 5 μg/dl and low to normal ACTH levels, suggestive of secondary adrenal insufficiency. Two of the 11 subjects have confirmed central adrenal insufficiency and are on hydrocortisone replacement and/or stress dosing during illness; 3 had normal and 1 had subnormal cortisol response to ACTH low-dose stimulation test but has not yet been started on therapy; the remaining 5 have upcoming stimulation testing planned. Our findings suggest that patients with PMM2-CDG may be at risk for adrenal insufficiency. Monitoring of morning cortisol and ACTH levels should be part of the standard care in patients with PMM2-CDG.
  • Case Report: Diffuse Polymicrogyria Associated With a Novel ADGRG1 Variant
    Publication . Carneiro, Fábio; Duarte, Júlia; Laranjeira, Francisco; Barbosa-Gouveia, Sofia; Couce, María-Luz; Fonseca, Maria José
    Pathogenic variants of the ADGRG1 gene are associated with bilateral frontoparietal polymicrogyria, defined radiologically by polymicrogyria with an anterior-posterior gradient, pontine and cerebellar hypoplasia and patchy white matter abnormalities. We report a novel homozygous ADGRG1 variant with atypical features. The patient presented at 8 months of age with motor delay, esotropia, hypotonia with hyporeflexia and subsequently developed refractory epilepsy. At the last assessment, aged 12 years, head control, sitting and language were not acquired. Magnetic resonance imaging revealed diffuse polymicrogyria with relative sparing of the anterior temporal lobes, without an anterior-posterior gradient, diffuse hypomyelination and pontine and cerebellar hypoplasia. A panel targeting brain morphogenesis defects yielded an unreported homozygous ADGRG1 nonsense variant (dbSNP rs746634404), present in the heterozygous state in both parents. We report a novel ADGRG1 variant associated with diffuse polymicrogyria without an identifiable anterior-posterior gradient, diffuse hypomyelination and a severe motor and cognitive phenotype. Our case highlights the phenotypic diversity of ADGRG1 pathogenic variants and the clinico-anatomical overlap between recognized polymicrogyria syndromes.
  • Genotype-Phenotype Correlations in PMM2-CDG
    Publication . Vaes, Laurien; Rymen, Daisy; Cassiman, David; Ligezka, Anna; Vanhoutvin, Nele; Quelhas, D; Morava, Eva; Witters, Peter
    PMM2-CDG is a rare disease, causing hypoglycosylation of multiple proteins, hence preventing full functionality. So far, no direct genotype-phenotype correlations have been identified. We carried out a retrospective cohort study on 26 PMM2-CDG patients. We collected the identified genotype, as well as continuous variables indicating the disease severity (based on Nijmegen Pediatric CDG Rating Score or NPCRS) and dichotomous variables reflecting the patients' phenotype. The phenotypic effects of patients' genotype were studied using non-parametric and Chi-Square tests. Seventeen different pathogenic variants have been studied. Variants with zero enzyme activity had no significant impact on the Nijmegen score. Pathogenic variants involving the stabilization/folding domain have a significantly lower total NPCRS (p = 0.017): presence of the p.Cys241Ser mutation had a significantly lower subscore 1,3 and NPCRS (p = 0.04) and thus result in a less severe phenotype. On the other hand, variants involving the dimerization domain, p.Pro113Leu and p.Phe119Leu, resulted in a significantly higher NPCRS score (p = 0.002), which indicates a worse clinical course. These concepts give a better insight in the phenotypic prognosis of PMM2-CDG, according to their molecular base.
  • Detailed Clinical and Psychological Phenotype of the X-linked HNRNPH2-Related Neurodevelopmental Disorder
    Publication . Bain, Jennifer M.; Thornburg, Olivia; Pan, Cheryl; Rome-Martin, Donnielle; Boyle, Lia; Fan, Xiao; Devinsky, Orrin; Frye, Richard; Hamp, Silke; Keator, Cynthia G.; LaMarca, Nicole M.; Maddocks, Alexis B.R.; Madruga-Garrido, Marcos; Niederhoffer, Karen Y.; Novara, Francesca; Peron, Angela; Poole-Di Salvo, Elizabeth; Salazar, Rachel; Skinner, Steven A.; Soares, Gabriela; Goldman, Sylvie; Chung, Wendy K.
    Objective: To expand the clinical phenotype of the X-linked HNRNPH2-related neurodevelopmental disorder in 33 individuals. Methods: Participants were diagnosed with pathogenic or likely pathogenic variants in HNRNPH2 using American College of Medical Genetics and Genomics/Association of Molecular Pathology criteria, largely identified via clinical exome sequencing. Genetic reports were reviewed. Clinical data were collected by retrospective chart review and caregiver report including standardized parent report measures. Results: We expand our clinical characterization of HNRNPH2-related disorders to include 33 individuals, aged 2-38 years, both females and males, with 11 different de novo missense variants, most within the nuclear localization signal. The major features of the phenotype include developmental delay/intellectual disability, severe language impairment, motor problems, growth, and musculoskeletal disturbances. Minor features include dysmorphic features, epilepsy, neuropsychiatric diagnoses such as autism spectrum disorder, and cortical visual impairment. Although rare, we report early stroke and premature death with this condition. Conclusions: The spectrum of X-linked HNRNPH2-related disorders continues to expand as the allelic spectrum and identification of affected males increases.
  • International consensus guidelines for phosphoglucomutase 1 deficiency (PGM1‐CDG): Diagnosis, follow‐up, and management
    Publication . Altassan, Ruqaiah; Radenkovic, Silvia; Edmondson, Andrew C.; Barone, Rita; Brasil, Sandra; Cechova, Anna; Coman, David; Donoghue, Sarah; Falkenstein, Kristina; Ferreira, Vanessa; Ferreira, Carlos; Fiumara, Agata; Francisco, Rita; Freeze, Hudson; Grunewald, Stephanie; Honzik, Tomas; Jaeken, Jaak; Krasnewich, Donna; Lam, Christina; Lee, Joy; Lefeber, Dirk; Marques‐da‐Silva, Dorinda; Pascoal, Carlota; Quelhas, D; Raymond, Kimiyo M.; Rymen, Daisy; Seroczynska, Malgorzata; Serrano, Mercedes; Sykut‐Cegielska, Jolanta; Thiel, Christian; Tort, Frederic; Vals, Mari‐Anne; Videira, Paula; Voermans, Nicol; Witters, Peter; Morava, Eva
    Phosphoglucomutase 1 (PGM1) deficiency is a rare genetic disorder that affects glycogen metabolism, glycolysis, and protein glycosylation. Previously known as GSD XIV, it was recently reclassified as a congenital disorder of glycosylation, PGM1-CDG. PGM1-CDG usually manifests as a multisystem disease. Most patients present as infants with cleft palate, liver function abnormalities and hypoglycemia, but some patients present in adulthood with isolated muscle involvement. Some patients develop life-threatening cardiomyopathy. Unlike most other CDG, PGM1-CDG has an effective treatment option, d-galactose, which has been shown to improve many of the patients' symptoms. Therefore, early diagnosis and initiation of treatment for PGM1-CDG patients are crucial decisions. In this article, our group of international experts suggests diagnostic, follow-up, and management guidelines for PGM1-CDG. These guidelines are based on the best available evidence-based data and experts' opinions aiming to provide a practical resource for health care providers to facilitate successful diagnosis and optimal management of PGM1-CDG patients.
  • NPC1 silent variant induces skipping of exon 11 (p.V562V) and unfolded protein response was found in a specific Niemann‐Pick type C patient
    Publication . 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, Sandra
    Background: 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.
  • Rare Pathogenic Copy Number Variation in the 16p11.2 (BP4–BP5) Region Associated with Neurodevelopmental and Neuropsychiatric Disorders: A Review of the Literature
    Publication . de Stefano, Maria Chiara; Gallagher, Louise; Rakic, Severin; Jorge, Paula; Cuturilo, Goran; Markovska-Simoska, Silvana; Borg, Isabella; Wolstencroft, Jeanne; Tümer, Zeynep; Harwood, Adrian J.; Kodra, Yllka; Skuse, David
    Copy number variants (CNVs) play an important role in the genetic underpinnings of neuropsychiatric/neurodevelopmental disorders. The chromosomal region 16p11.2 (BP4-BP5) harbours both deletions and duplications that are associated in carriers with neurodevelopmental and neuropsychiatric conditions as well as several rare disorders including congenital malformation syndromes. The aim of this article is to provide a review of the current knowledge of the diverse neurodevelopmental disorders (NDD) associated with 16p11.2 deletions and duplications reported in published cohorts. A literature review was conducted using the PubMed/MEDLINE electronic database limited to papers published in English between 1 January 2010 and 31 July 2020, describing 16p11.2 deletions and duplications carriers' cohorts. Twelve articles meeting inclusion criteria were reviewed from the 75 articles identified by the search. Of these twelve papers, eight described both deletions and duplications, three described deletions only and one described duplications only. This study highlights the heterogeneity of NDD descriptions of the selected cohorts and inconsistencies concerning accuracy of data reporting.
  • Development and Validation of a Mathematical Model to Predict the Complexity of FMR1 Allele Combinations
    Publication . Rodrigues, Bárbara; Vale-Fernandes, Emídio; Maia, N; Santos, Flávia; Marques, Isabel; Santos, Rosário; Nogueira, António J. A.; Jorge, Paula
    The polymorphic trinucleotide repetitive region in the FMR1 gene 5'UTR contains AGG interspersions, particularly in normal-sized alleles (CGG < 45). In this range repetitive stretches are typically interrupted once or twice, although alleles without or with three or more AGG interspersions can also be observed. AGG interspersions together with the total length of the repetitive region confer stability and hinder expansion to pathogenic ranges: either premutation (55 < CGG < 200) or full mutation (CGG > 200). The AGG interspersions have long been identified as one of the most important features of FMR1 repeat stability, being particularly important to determine expansion risk estimates in female premutation carriers. We sought to compute the combined AGG interspersion numbers and patterns, aiming to define FMR1 repetitive tract complexity combinations. A mathematical model, the first to compute this cumulative effect, was developed and validated using data from 131 young and healthy females. Plotting of their allelic complexity enabled the identification of two statistically distinct groups - equivalent and dissimilar allelic combinations. The outcome, a numerical parameter designated allelic score, depicts the repeat substructure of each allele, measuring the allelic complexity of the FMR1 gene including the AGGs burden, thus allowing new behavioral scrutiny of normal-sized alleles in females.
  • Two Compound Heterozygous Variants in SNX14 Cause Stereotypies and Dystonia in Autosomal Recessive Spinocerebellar Ataxia 20
    Publication . Maia, N; Soares, Gabriela; Silva, Cecília; Marques, Isabel; Rodrigues, Bárbara; Santos, Rosário; Melo-Pires, Manuel; de Brouwer, Arjan PM; Temudo, Teresa; Jorge, Paula
    Autosomal Recessive Spinocerebellar Ataxia 20, SCAR20, is a rare condition characterized by intellectual disability, lack of speech, ataxia, coarse facies and macrocephaly, caused by SNX14 variants. While all cases described are due to homozygous variants that generally result in loss of protein, so far there are no other cases of reported compound heterozygous variants. Here we describe the first non-consanguineous SCAR20 family, the second Portuguese, with two siblings presenting similar clinical features caused by compound heterozygous SNX14 variants: NM_001350532.1:c.1195C>T, p.(Arg399*) combined with a novel complex genomic rearrangement. Quantitative PCR (Q-PCR), long-range PCR and sequencing was used to elucidate the region and mechanisms involved in the latter: two deletions, an inversion and an AG insertion: NM_001350532.1:c.[612+3028_698-2759del;698-2758_698-516inv;698-515_1171+1366delinsAG]. In silico analyses of these variants are in agreement with causality, enabling a genotype-phenotype correlation in both patients. Clinical phenotype includes dystonia and stereotypies never associated with SCAR20. Overall, this study allowed to extend the knowledge of the phenotypic and mutational spectrum of SCAR20, and to validate the role of Sorting nexin-14 in a well-defined neurodevelopmental syndrome, which can lead to cognitive impairment. We also highlight the value of an accurate clinical evaluation and deep phenotyping to disclose the molecular defect underlying highly heterogeneous condition such as intellectual disability.
  • EMQN best practice guidelines for genetic testing in dystrophinopathies
    Publication . Fratter, Carl; Dalgleish, Raymond; Allen, Stephanie K.; Santos, Rosário; Abbs, Stephen; Tuffery-Giraud, Sylvie; Ferlini, Alessandra
    Dystrophinopathies are X-linked diseases, including Duchenne muscular dystrophy and Becker muscular dystrophy, due to DMD gene variants. In recent years, the application of new genetic technologies and the availability of new personalised drugs have influenced diagnostic genetic testing for dystrophinopathies. Therefore, these European best practice guidelines for genetic testing in dystrophinopathies have been produced to update previous guidelines published in 2010.These guidelines summarise current recommended technologies and methodologies for analysis of the DMD gene, including testing for deletions and duplications of one or more exons, small variant detection and RNA analysis. Genetic testing strategies for diagnosis, carrier testing and prenatal diagnosis (including non-invasive prenatal diagnosis) are then outlined. Guidelines for sequence variant annotation and interpretation are provided, followed by recommendations for reporting results of all categories of testing. Finally, atypical findings (such as non-contiguous deletions and dual DMD variants), implications for personalised medicine and clinical trials and incidental findings (identification of DMD gene variants in patients where a clinical diagnosis of dystrophinopathy has not been considered or suspected) are discussed.