Percorrer por autor "Miranda, Beatriz"
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- Cascade Screening in Familial Hypercholesterolemia: Adult cascade screening versus CHILD reverse cascade screeningPublication . Miranda, Beatriz; Medeiros, Ana Margarida; Alves, Ana Catarina; Bourbon, MafaldaFamilial hypercholesterolemia (FH) is an inherited lipid disorder that increases the risk of developing cardiovascular disease (CVD). Despite most cascade screening programs are initiated by adult index cases, reverse cascade screening pediatric index cases is starting to be described. Therefore, in this work, we aimed to assess the outcome of both creening strategies (adult cascade screening and child reverse cascade screening) in families from the Portuguese FH Study (PFHS). The PFHS database was consulted, and 423 index cases genetically identified with FH (224 adults and 199 children) and their 997 relatives referred to the PFHS were analysed. From 224 adults with FH, 485 relatives were enrolled for cascade screening and 290 were identified with FH. From 199 paediatric cases with FH, 512 relatives were screened and 286 were identified with FH. Child reverse cascade screening presented a slightly higher diagnostic rate than adult cascade screening, 1.44 vs 1.29 new cases with FH per index case, and the age of the relatives identified was younger, 29 vs 37 years. For 94% of index children, relatives were referred (2.56 relatives per index), in contrast with the adult cohort whereas only 70% were referred with family-members (2.17 relatives per index). Overall, both screening approaches constitute valuable tools to identify new cases with FH, but the child reverse cascade screening notably creates the opportunity for more relatives to be tested at a younger age. However, it remains crucial to improve relatives' recruitment rate since early identification allows a correct FH diagnosis and treatment to prevent CVD.
- Estudo Português de Hipercolesterolemia Familiar (1999-2021): relação fenótipo-genótipoPublication . Medeiros, Ana Margarida; Alves, Ana Catarina; Chora, Joana Rita; Miranda, Beatriz; Bourbon, Mafalda; em nome dos investigadores do Estudo Português de Hipercolesterolemia FamiliarA Hipercolesterolemia Familiar (FH) é uma condição genética comum do metabolismo dos lípidos, que se encontra subdiagnosticada. Existem três genes primários associados à FH (LDLR, APOB e PCSK9) e 5 genes fenocópias (LDLRAP1, LIPA, ABCG5, ABCG8 e APOE), que conferem um fenótipo semelhante à FH. Neste trabalho pretende-se apresentar a relação fenótipo-genótipo dos indivíduos com critérios clínicos de FH referenciados ao Estudo Português de Hipercolesterolemia Familiar. Até ao fim de 2021 foram estudados molecularmente 1005 indivíduos com critérios clínicos de FH. Destes, foram confirmados geneticamente com FH (FH positivos), 417 casos-índex (408 heterozigotos e 9 homozigotos). Com os estudos familiares identificaram- se adicionalmente 581 heterozigotos e 2 homozigotos. De entre os FH positivos, os casos-índex com variantes de alelo nulo apresentam um fenótipo mais severo do que os casos-índex com variantes de alelo defeituoso. Cerca de 1% dos casos-índex foram diagnosticados com outras causas monogénicas. Dos FH negativos, 34% apresenta hiper-Lp(a), 18% tem uma hipercolesterolemia de causa poligénica e 1% possui uma variante patogénica em heterozigotia nos genes fenocópias da FH. As diferentes causas genéticas contribuem para uma variedade de fenótipos que requerem diferentes formas de gestão da doença, terapias específicas e têm implicações na estratificação do risco cardiovascular e no rastreio dos familiares, sendo por esta razão essencial que seja identificada a etiologia da hipercolesterolemia o mais precocemente possível para melhorar o prognóstico dos indivíduos com FH.
- Familial chylomicronemia syndrome in PortugalPublication . Alves, Ana Catarina; Miranda, Beatriz; Sequeira, Sílvia; Moldovan, Oana; Nunes, Catarina; Antunes, Henedina; Martins, Esmeralda; Gonçalves, Rute; Duarte, Sequeira; Guerra, António; Gaspar, Ana; Salgado, Miguel; Azevedo, Aida; Araújo, Francisco; Ferreira, Ana Cristina; Rato, Quitéria; Palma, Isabel; Bourbon, MafaldaFamilial chylomicronemia syndrome (FCS) is a rare autosomal recessive disorder of lipoprotein metabolism. It is characterized by marked elevation of triglyceride and chylomicron levels, lipaemic plasma, recurrent pancreatitis, eruptive xanthoma, hepatosplenomegaly, andliapemiaretinalis. All genes associated with FCS (LPL, APOC2, APOA5, LMF1 and GPHBP1) have an effect on the activity of lipoprotein lipase (LPL). The aim of this study is to present all cases with FCS clinical diagnosis, studied in our laboratory.
- Hipercolesterolemia familiar homozigótica em Portugal: caracterização de casos diagnosticados geneticamente no âmbito do Estudo Português de Hipercolesterolemia Familiar, 1999-2023Publication . Medeiros, Ana Margarida; Alves, Ana Catarina; Miranda, Beatriz; Chora, Joana Rita; Aguiar, Patrício; Amaro, Mário; Bruges, Margarida; Ferreira, Sofia; Furtado, António; Gaspar, Ana; Gonçalves, Filipa Sousa; Lobarinhas, Goreti; Lourenço, Guilherme; Martins, Paula; Antunes, Sofia Moura; Palma, Isabel; Rato, Quitéria; Torres, Diogo; Rico, Miguel Toscano; Travessa, André; Bourbon, MafaldaHipercolesterolemia Familiar (FH) é uma condição autossómica semidominante causada por variantes patogénicas ou provavelmente patogénicas nos genes LDLR, APOB e PCSK9. A FH pode apresentar-se na forma monoalélica (FH heterozigótica) ou bialélica (FH homozigótica). A forma homozigótica é mais rara e com fenótipo mais grave. Indivíduos com FH homozigótica geralmente apresentam hipercolesterolemia severa (LDL>400mg/dL), xantomas e doença cardiovascular aterosclerótica (DCVA) prematura em idade jovem. Até 2023, foram referenciados ao Estudo Português de Hipercolesterolemia Familiar 1291 casos-índex. Neste estudo foram analisados os casos com FH homozigótica. Foram identificados 15 casos com FH homozigótica: 5 com a mesma variante bialélica no LDLR, 7 com variantes bialélicas diferentes no LDLR, 1 com variantes bialélicas diferentes no PCSK9, e 2 com variantes nos genes LDLR e APOB. A maioria dos indivíduos eram adultos (73%) e do sexo feminino (87%), 13% apresentando xantomas tendinosos e 36% com DCVA. Variantes de alelo nulo estão associadas a um fenótipo mais grave e a uma menor resposta ao tratamento, sendo necessária terapêutica independente da atividade do recetor de LDL. O diagnóstico genético permite identificar com precisão as variantes e os tipos de alelos, e implementar uma abordagem terapêutica mais personalizada nestes indivíduos.
- Proposal of a Familial Hypercholesterolemia Pediatric Diagnostic Score (FH-PeDS)Publication . Kafol, Jan; Miranda, Beatriz; Sikonja, Rok; Sikonja, Jaka; Wiegman, Albert; Medeiros, Ana Margarida; Alves, Ana Catarina; Freiberger, Tomas; Hutten, Barbara A.; Mlinaric, Matej; Battelino, Tadej; Humphries, Steve E.; Bourbon, Mafalda; Groselj, UrhBackground and aims: Familial hypercholesterolemia (FH) significantly increases cardiovascular risk from childhood yet remains widely underdiagnosed. This cross-sectional study aimed to evaluate existing pediatric FH diagnostic criteria in real-world cohorts and to develop two novel diagnostic tools: a semi-quantitative scoring system (FH-PeDS) and a machine learning model (ML-FH-PeDS) to enhance early FH detection. Methods: Five established FH diagnostic criteria were assesed (Dutch Lipid Clinics Network [DLCN], Simon Broome, EAS, Simplified Canadian, and Japanese Atherosclerosis Society) in Slovenian (N=1,360) and Portuguese (N=340) pediatric hypercholesterolemia cohorts, using FH-causing variants as the reference standard. FH-PeDS was developed from the Slovenian cohort, and ML-FH-PeDS was trained and tested using a 60%/40% split before external validation in the Portuguese cohort. Results: Only 47.4% of genetically confirmed FH cases were identified by all established criteria, while 10.9% were missed entirely. FH-PeDS outperformed DLCN in the combined cohort (AUC 0.897 vs. 0.857; p<0.01). ML-FH-PeDS showed superior predictive power (AUC 0.932 in training, 0.904 in testing vs. 0.852 for DLCN; p<0.01) and performed best as a confirmatory test in the testing subgroup (39.7% sensitivity, 87.7% PPV at 98% specificity). In the Portuguese cohort, ML-FH-PeDS maintained strong predictive performance (AUC 0.867 vs. 0.815 for DLCN; p<0.01) despite population differences. Conclusions: Current FH diagnostic criteria perform suboptimally in children. FH-PeDS and ML-FH-PeDS provide tools to improve FH detection, particularly where genetic testing is limited. They also help guide genetic testing decisions for hypercholesterolemic children. By enabling earlier diagnosis and intervention, these tools may reduce long-term cardiovascular risk and improve outcomes.
- Rare dyslipidaemias associated with LDL cholesterol valuesPublication . Alves, Ana Catarina; Miranda, Beatriz; Bourbon, Mafalda; em nome dos investigadores do estudo de dislipidemia familiaresIntroduction: Dyslipidaemia is a disorder of lipid metabolism, characterized by either an increase or decrease in lipid particles; Most hyperlipidaemia confer an increased cardiovascular risk; hypolipidaemia, such as abeta or hypobetalipoproteinemia, may present different manifestations ranging from poor weight progression to neurological manifestations.
- Rare primary dyslipidaemias associated with low LDL and HDL cholesterol values in PortugalPublication . Alves, Ana Catarina; Miranda, Beatriz; Moldovan, Oona; Espírito Santo, Raquel; Gouveia Silva, Raquel; Soares Cardoso, Sandra; Diogo, Luísa; Seidi, Mónica; Sequeira, Sílvia; Bourbon, MafaldaDyslipidaemia represents a group of disorders of lipid metabolism, characterized by either an increase or decrease in lipid particles, usually associated with triglycerides, LDL cholesterol (LDL-C) and/or HDL cholesterol (HDL-C). Most hyperlipidaemias and HDL deficiencies confer an increased cardiovascular risk, while hypolipidaemia, such as abeta or hypobetalipoproteinemia, may present different manifestations ranging from poor weight progression to neurological manifestations. The aim of this study is to present 7 cases with rare dyslipidaemias associated with low LDL or low HDL cholesterol values, referred to our laboratory for the genetic identification of the cause of the dyslipidaemia. Lipid profile was determined for each individual in an automated equipment Integra Cobas (Roche). Molecular analysis was performed by NGS with a target panel of 57 genes involved in lipid metabolism (Sure select QXT, Agilent) and samples were run in a NextSEQ Sequencer (Illumina). Only genes associated to rare forms of low HDL-c or LDL-c were analysed for this work, namely: ABCA1, APOA1, LCAT, SCARB1, APOB, PCSK9, MTTP, SAR1B, and ANGPTL3. All rare variants (MAF<5%) found in these genes were confirmed by Sanger sequencing. This study includes 7 index cases (IC), with the following clinical diagnoses: Fish Eye Disease (1), Hypoalphalipoproteinemia (1) and Abetalipoproteinemia (ABL) / Familial Hypobetalipoproteinemia (FHBL) (5). We have identified one IC with a compound heterozygosity in LCAT causing Fish Eye Disease and one IC with a variant in ABCA1 in homozygosity causing Tangier disease. We found variants causing homozygous FHBL in 2 IC, one of whom has an undescribed pathogenic variant in homozygosity in APOB (c.12087+1G>A) and the other is a possible compound heterozygous for APOB variants c.2604+1G>A and c.4651C>T/p.(Gln1551*). In two patients only a variant in heterozygosity (c.3365delG/p.(Gly1122Vfs*62) and c.11095A>T/p.(Arg3699*)). In the remaining patient, no variants were identified. NGS proved to be a fundamental key for genetic testing of rare lipid disorders, allowing us to find the genetic cause of disease in 6/7 patients with low HDL-c and LDL-c. Patients with these rare conditions should be identified as early as possible in order to minimize or prevent clinical manifestations. The unsolved case is still under investigation.
- Sitosterolemia In iberoamerican countries: 16 new cases and phenotype genotype analysisPublication . Alves, Ana Catarina; Chora, Joana Rita; Miranda, Beatriz; Medeiros, Ana Margarida; Graça, Rafael; Bañares, Virginia G.; Araujo, Maria Beatriz; Vilagut, Ferrán Trías; Soler, Cristina; Meavilla, Silvia; Toledo, Maria J. Benitez; Volpe, Camila Garcia; Reyes, Ximena; Dell'Oca, Nicolás; Martins, Paula; Marado, Diana; Vilarinho, Laura; Dias, Aureliano Jorge; Ferreira, Ana Cristina; Padeira, Gonçalo; Casañas, Marta; Alegre-González, Diana; Lozano, José Mosquera; Aguiar, Patrício; Gonçalves, Filipa Sousa; Ernaga, Ander; Apellaniz-Ruiz, Maria; Rubi, Rodrigo; Figueroa, Nahún Muñoz; Vasquez, Norma Alejandra; Valdivielso, Pedro; Bourbon, Mafalda; ElsevierBackground: Sitosterolemia is a rare autosomal recessive lipid disorder caused by biallelic pathogenic variants in ABCG5 or ABCG8 genes. It is characterized by elevated plasma plant sterol concentrations, xanthomas, and an increased risk of premature cardiovascular disease. As happens with familial hypercholesterolemia (FH), sitosterolemia is subdiagnosed and is frequently confounded with FH, resulting in inappropriate management. This study aims to describe newly identified cases across Iberoamerican countries and to highlight the need for improved diagnostic strategies. Methods: We report 16 cases of molecularly confirmed sitosterolemia from 5 Iberoamerican countries (Argentina, Mexico, Portugal, Spain, and Uruguay), including 12 index cases and 4 relatives identified by cascade screening. Clinical, biochemical, and molecular data were collected and analyzed. β-sitosterol levels were measured when possible, and variant classification followed American College of Medical Genetics and Genomics (ACMG) guidelines with disease-specific adaptations. Results: Fifteen individuals had biallelic variants in ABCG8 and 1 had a homozygous frameshift variant in ABCG5. Ten distinct ABCG8 variants were identified, including 7 nonsense and 3 missense variants. Xanthomas were observed in 56% of cases. Most cases were initially diagnosed as FH, with a diagnostic delay of up to 30 years. Treatment with ezetimibe, alone or combined with statins, led to biochemical and clinical improvement, including xanthoma regression in some cases. Conclusion: Sitosterolemia remains underdiagnosed due to lack of systematic screening and clinical overlap with FH. Our findings highlight the importance of including ABCG5/8 in genetic testing panels and of recognizing clinical clues for early diagnosis, enabling targeted treatment and prevention of adverse outcomes. Adapted ACMG variant classification improves interpretability for ABCG5/8-related sitosterolemia.
- Unraveling the genetic background of individuals with a clinical familial hypercholesterolemia phenotypePublication . Medeiros, Ana Margarida; Alves, Ana Catarina; Miranda, Beatriz; Chora, Joana Rita; Bourbon, Mafalda; investigators of the Portuguese FH StudyFamilial hypercholesterolemia (FH) is a common genetic disorder of lipid metabolism caused by pathogenic/likely pathogenic variants in LDLR, APOB, and PCSK9 genes. Variants in FH-phenocopy genes (LDLRAP1, APOE, LIPA, ABCG5, and ABCG8), polygenic hypercholesterolemia, and hyperlipoprotein (a) [Lp(a)] can also mimic a clinical FH phenotype. We aim to present a new diagnostic tool to unravel the genetic background of clinical FH phenotype. Biochemical and genetic study was performed in 1,005 individuals with clinical diagnosis of FH, referred to the Portuguese FH Study. A next-generation sequencing panel, covering eight genes and eight SNPs to determine LDL-C polygenic risk score and LPA genetic score, was validated, and used in this study. FH was genetically confirmed in 417 index cases: 408 heterozygotes and 9 homozygotes. Cascade screening increased the identification to 1,000 FH individuals, including 11 homozygotes. FH-negative individuals (phenotype positive and genotype negative) have Lp(a) >50 mg/dl (30%), high polygenic risk score (16%), other monogenic lipid metabolism disorders (1%), and heterozygous pathogenic variants in FH-phenocopy genes (2%). Heterozygous variants of uncertain significance were identified in primary genes (12%) and phenocopy genes (7%). Overall, 42% of our cohort was genetically confirmed with FH. In the remaining individuals, other causes for high LDL-C were identified in 68%. Hyper-Lp(a) or polygenic hypercholesterolemia may be the cause of the clinical FH phenotype in almost half of FH-negative individuals. A small part has pathogenic variants in ABCG5/ABCG8 in heterozygosity that can cause hypercholesterolemia and should be further investigated. This extended next-generation sequencing panel identifies individuals with FH and FH-phenocopies, allowing to personalize each person's treatment according to the affected pathway.