Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis
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Browsing Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis by Field of Science and Technology (FOS) "Ciências Médicas"
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- Bridging Genetic Insights with Neuroimaging in Autism Spectrum Disorder - A Systematic ReviewPublication . Vilela, Joana; Rasga, Célia; Santos, João Xavier; Martiniano, Hugo; Marques, Ana Rita; Oliveira, Guiomar; Vicente, Astrid Moura; MDPIAutism Spectrum Disorder (ASD) is an early onset neurodevelopmental disorder characterized by impaired social interaction and communication, and repetitive patterns of behavior. Family studies show that ASD is highly heritable, and hundreds of genes have previously been implicated in the disorder; however, the etiology is still not fully clear. Brain imaging and electroencephalography (EEG) are key techniques that study alterations in brain structure and function. Combined with genetic analysis, these techniques have the potential to help in the clarification of the neurobiological mechanisms contributing to ASD and help in defining novel therapeutic targets. To further understand what is known today regarding the impact of genetic variants in the brain alterations observed in individuals with ASD, a systematic review was carried out using Pubmed and EBSCO databases and following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This review shows that specific genetic variants and altered patterns of gene expression in individuals with ASD may have an effect on brain circuits associated with face processing and social cognition, and contribute to excitation–inhibition imbalances and to anomalies in brain volumes.
- Functional characterization of 16 variants found in the LDL receptor genePublication . Konečná, Kateřina; Přerovská, Tereza; Loja, Tomáš; Fajkusová, Lenka; Koutná, Jana; Kramárek, Michal; Alves, Ana Catarina; Bourbon, Mafalda; Freiberger, Tomáš; Tichý, LukášFamilial hypercholesterolemia (FH) is a disorder of cholesterol metabolism characterized by elevated LDL-cholesterol levels. The most common cause of FH is pathogenic variants in the LDL receptor (LDLR) gene. To shed light on the functional impact of selected LDLR variants, we functionally characterized 16 LDLR genetic variants alongside 10 control variants. We performed in vitro assays based on transient expression of WT and mutant LDLRs in LDLR-deficient Chinese hamster ovary cells. We used flow cytometry to analyze the relative amount of LDLRs expressed on the cell surface and the relative amount of internalized LDL. In addition, we analyzed the expression and maturation of LDLR protein by Western blotting. Of the 16 studied variants, two variants (p.(Asn272Thr) and p.(Arg574Leu)) did not exhibit a defect in LDLR function, one variant (p.(Ala540Thr)) exhibited a defect in LDL binding and/or internalization despite normal LDLR cell surface expression, and the remaining 13 variants had a detrimental effect on both LDLR cell surface expression and LDL internalization. The information presented in this study contributes to the clinical classification of LDLR variants and a more precise diagnosis of FH patients, highlighting the type of defect each variant produces.
- The Functional Landscape Of Coding Variation In The Familial Hypercholesterolemia Gene LDLRPublication . Tabet, Daniel R.; Coté, Atina G.; Lancaster, Megan C.; Weile, Jochen; Rayhan, Ashyad; Fotiadou, Iosifina; Kishore, Nishka; Li, Roujia; Kuang, Da; Knapp, Jennifer J.; Carrero, Carmela Serio; Taverniti, Olivia; Axakova, Anna; Castelli, Jack M. P.; Islam, Mohammad Majharul; Sowlati-Hashjin, Shahin; Gandhi, Aanshi; Maaieh, Ranim; Garton, Michael; Matreyek, Kenneth; Fowler, Douglas M.; Bourbon, Mafalda; Pfisterer, Simon G.; Glazer, Andrew M.; Kroncke, Brett M.; Parikh, Victoria N.; Ashley, Euan A.; Knowles, Joshua W.; Claussnitzer, Melina; Cirulli, Elizabeth T.; Hegele, Robert A.; Roden, Dan M.; MacRae, Calum A.; Roth, Frederick P.Variants in the familial hypercholesterolemia gene -the most important genetic driver of cardiovascular disease-can raise circulating low-density lipoprotein (LDL) cholesterol concentrations and increase the risk of premature atherosclerosis. Definitive classifications are lacking for nearly half of clinically encountered missense variants, limiting interventions that reduce disease burden. Here, we tested the impact of ~17,000 (nearly all possible) missense coding variants on both LDLR cell-surface abundance and LDL uptake, yielding sequence-function maps that recapitulate known biochemistry, offer functional insights, and provide evidence for interpreting clinical variants. Functional scores correlated with hyperlipidemia phenotypes in prospective human cohorts and augmented polygenic scores to improve risk inference, highlighting the potential of this resource to accelerate familial hypercholesterolemia diagnosis and improve patient outcomes.
- Neurometabolic profiles of autism spectrum disorder patients with genetic variants in specific neurotransmission and synaptic genesPublication . Vilela, Joana; Pereira, Andreia C.; Violante, Inês R.; Mouga, Susana; Rasga, Célia; Santos, João Xavier; Martiniano, Hugo; Marques, Ana Rita; Oliveira, Guiomar; Castelo-Branco, Miguel; Vicente, Astrid MouraAutism Spectrum Disorder (ASD) is a neurodevelopmental condition characterized by impaired social interaction, and restricted and repetitive patterns of behavior. ASD presents as a clinical spectrum, with variable levels of severity and multiple co-occurring conditions. The etiology of ASD may involve hundreds of genes and there is evidence that neurotransmitter and synaptic (NS) pathways are implicated. Proton Magnetic Resonance Spectroscopy (H-MRS) has made it possible to study the concentration of brain neurometabolites and compare their levels in the brains of ASD and control individuals. We integrated genetic variants in NS genes with H-MRS analysis, and identified 12 predicted damaging variants (PDVs) in 12 NS genes in 10 ASD individuals, most mapping to genes involved in Gamma-aminobutyric acid (GABA) and glutamate pathways. Total creatine (tCr) and total N-acetyl aspartate (tNAA), markers of bioenergetics and neuronal metabolism, respectively, were lower in ASD patients with genetic alterations in NS genes compared to a control group without ASD. We conclude that PDVs in NS genes that are important for the regulation of glutamate or involved in GABAergic functions are associated with neurometabolic alterations, and that dysfunction in glutamatergic and/or GABAergic pathways may be implicated as these pathways are linked to the metabolic measures altered in cases.
- 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.
- 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.