Pharmacogenetics of hypercholesterolemia drugs

Doentes com dislipidemia grave necessitam de tomar medicação antidislipidémica para diminuir as concentrações elevadas de colesterol de forma a reduzirem o seu elevado risco cardiovascular. Distintos tipos e/ou doses de estatinas levam a diferentes níveis de redução dos níveis de LDL-C, mas existe uma grande variação interpessoal na resposta, que se pensa estar associada a variantes nos genes envolvidos na farmacodinâmica e farmacocinética desta classe de fármacos. Este trabalho tem como objetivo determinar a prevalência de genótipos associados a uma menor eficácia ou a um maior risco de efeitos secundários adversos no tratamento com estatinas na população portuguesa. Foram genotipados vários SNPs envolvidos no metabolismo, absorção, transporte e/ou excreção dos vários tipos de estatinas numa amostra de adultos da população portuguesa proveniente das diferentes regiões do país. A variante SLCO1B1*5, associada com um maior risco de desenvolver miopatia com o tratamento com sinvastatina, tem uma frequência 2 vezes superior na nossa amostra do que o descrito nas bases de dados populacionais. Este fato, aliado ao grande aumento de consumo nacional de estatinas, principalmente de sinvastatina, é um fator importante que deve ser considerado na tomada de decisão da prescrição de antidislipidémicos.Patients with severe dyslipidaemia need to take antidislipidemic medication to lower the high cholesterol concentrations to decrease their increased cardiovascular risk. Different types and/or dose of statins lead to different levels of LDL-C reduction, but there is a large interpersonal variation in the response, which is thought to be associated with variants in genes involved in pharmacodynamics and pharmacokinetics of this class of drugs. This work aims to determine the prevalence of genotypes associated with a lower efficacy or a higher risk of adverse side effects in the treatment with statins in the Portuguese population. Several SNPs involved in the metabolism, absorption, transport and/or excretion of the various types of statins were genotyped in a sample of adults from the Portuguese population from different regions of the country. The SLCO1B1*5 variant, associated with an increased risk of developing myopathy on simvastatin treatment, has a frequency 2 times higher in our sample than described in the population databases. This fact, coupled with the large increase in national consumption of statins, mainly simvastatin, is an important factor that should be considered in the decision-making of the prescription of antidislipidemics.info:eu-repo/semantics/publishedVersio

Portuguese Familial Hypercholesterolaemia Study

A Hipercolesterolemia Familiar (FH) é uma doença genética associada a um elevado risco cardiovascular. Doentes com FH possuem valores muito elevados de colesterol no plasma, desde o nascimento. Até à data 3 genes foram associados à FH: LDLR (85-90%), APOB (5-8%) e PCSK9 (1-2%). Em 1999 foi estabelecido, no Instituto Nacional de Saúde Doutor Ricardo Jorge, o Estudo Português de Hipercolesterolemia Familiar (EPHF). Este estudo de investigação tem como objetivo principal identificar a causa genética da dislipidemia em doentes com critérios clínicos de FH. O EPHF identificou molecularmente 718 doentes heterozigotos com uma variante patogénica ou provavelmente patogénica (segundo as diretrizes da ACMG) num dos 3 genes associados à FH. Adicionalmente, 90 indivíduos possuem uma das 35 variantes de significado incerto cuja patogenicidade necessita de ser avaliada através de estudos funcionais. Foram também identificados 10 homozigotos (3 homozigotos verdadeiros e 7 heterozigotos compostos), com variantes patogénicas nos genes LDLR e PCSK9. O EPHF conseguiu identificar 3,8% dos portugueses que se calcula terem FH, colocando Portugal entre os dez países com mais doentes identificados. O risco cardiovascular dos doentes com FH é determinado pelos valores elevados de colesterol que os doentes apresentam desde o nascimento, mas também pela patogenicidade da variante identificada. A identificação precoce dos doentes com FH, através do diagnóstico genético, permite ao clínico implementar medidas terapêuticas adequadas e mais agressivas, de modo a diminuir o risco cardiovascular inerente a estes doentes.Familial Hypercholesterolemia (FH) is a genetic disorder associated with a high cardiovascular risk. Patients with FH have very high plasma cholesterol values since birth. Until now three genes have been associated to FH: LDLR (85-90%), APOB (5-8%) and PCSK9 (1-2%). In 1999 the Portuguese FH (PFHS) Study was established at the National Institute of Health. This study aims to identify the genetic cause of dyslipidemia in patients with clinical diagnosis of FH. The Portuguese FH Study genetically identified 718 heterozygous patients with a pathogenic or probably pathogenic variant (according to ACMG guidelines) in one of the 3 genes associated to FH. In addition, 90 individuals have one of 35 variants of uncertain significance whose pathogenicity needs to be assessed through functional studies. Ten homozygotes (3 true homozygotes and 7 heterozygous compounds) were also identified, with pathogenic variants in the LDLR and PCSK9 genes. The PFHS was able to identify 3.8% of the Portuguese that are estimated to have FH, placing Portugal among the ten countries with the most patients identified. The cardiovascular risk of FH patients is determined by the high cholesterol values present since birth, but also by the pathogenicity of the identified variant. The early identification of these patients through genetic diagnosis allows the clinician to implement appropriate and more aggressive therapeutic measures in order to reduce the cardiovascular risk inherent to these patients.info:eu-repo/semantics/publishedVersio

Unraveling the genetic background of individuals with a clinical familial hypercholesterolemia phenotype

investigators of the Portuguese FH Study: Mafalda Bourbon, Quitéria Rato, Ana Catarina Alves, Ana Margarida Medeiros, Ana Catarina Gomes, Ana Cristina Ferreira, Ana Gaspar, Ana Margarida Marques, Ana Maria Garabal, Ana Paula Bogalho, Ana Rita Pereira, Anabela Raimundo, André Travessa, Andreia Lopes, António Afonso, António Furtado, António Guerra, António Monteiro, António Trindade, Armindo Ribeiro, Bernardo Dias Pereira, Bernardo Marques, Carla Laranjeira, Catarina Senra Moniz, Cecília Frutuoso, Cláudia Falcão Reis, Cláudia Rodrigues, Clementina Fernandes, Conceição Ferreira, Daniel Ferreira, Diogo Torres, Elisabete Martins, Elsa Gaspar, Fabiana Pimentel, Fernando Simões, Francisco Araújo, Francisco Silva, Goreti Lobarinhas, Graça Morais, Guida Gama, Guilherme Lourenço, Helena Mansilha, Helena Pereira, Heloísa Santos, Henedina Antunes, Inês Batista Gomes, Inês Colaço, Isabel Azevedo, Isabel Palma, João Anselmo, João Porto, João Ramos, João Sequeira Duarte, Jorge Pintado Alves, José Miguel Salgado, José Pereira de Moura, Leonor Sassetti, Lina Cardoso Ramos, Luísa Diogo Matos, Luísa Mota Vieira, Luísa Pires, Márcio de Moura, Margarida Bruges, Margarida Venâncio, Maria do Rosário Barroso, Maria João Virtuoso, Maria Luísa Gonçalves, Mário Martins Oliveira, Mendes Nunes, Miguel Costa, Miguel Mendes, Miguel Toscano Rico, Mónica Tavares, Natalina Miguel, Oana Moldovan, Olga Azevedo, Patrícia Lipari Pinto, Patrícia Pais, Patrícia Vasconcelos, Paula Garcia, Paula Martins, Pedro Marques da Silva, Piedade Lemos, Quitéria Rato, Raquel Coelho, Raquel Gouveia da Silva, Raquel Ribeiro, Rita Jotta de Oliveira, Roberto Pinto, Sandra Pereira, Sérgio Ferreira Cristina, Sílvia Sequeira, Susana Correia, Tânia Vassalo, Tiago Pack, Vânia Martins, Vera Frazão Vieira.Familial 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.Was supported by the Portuguese Cardiology Society (grant number: D13123) and FCT (grant numbers: PTDC/SAU-GMG/101874/2008 and PTDC/SAUSER/29180/2017). This work was also supported by UIDB/04046/2020 (DOI: 10.54499/UIDB/04046/2020) and UIDP/04046/2020 (DOI: 10.54499/UIDP/04046/2020) center grants from FCT, Portugal (to BioISI).info:eu-repo/semantics/publishedVersio

Genetic Characteristics of Latvian Patients with Familial Hypercholesterolemia: The First Analysis from Genome-Wide Sequencing

This article belongs to the Special Issue New Possibilities for the Treatment of DyslipidemiasBackground: There is limited data on the genetic characteristics of patients with familial hypercholesterolemia (FH) in Latvia. We aim to describe monogenic variants in patients from the Latvian Registry of FH (LRFH). Methods: Whole genome sequencing with 30 coverage was performed in unrelated index cases from the LRFH and the Genome Database of Latvian Population. LDLR, APOB, PCSK9, LDLRAP1, ABCG5, ABCG8, LIPA, LPA, CYP27A1, and APOE genes were analyzed. Only variants annotated as pathogenic (P) or likely pathogenic (LP) using the FH Variant Curation Expert Panel guidelines for LDLR and adaptations for APOB and PCSK9 were reported. Results: Among 163 patients, the mean highest documented LDL-cholesterol level was 7.47 1.60 mmol/L, and 79.1% of patients had LDL-cholesterol 6.50 mmol/L. A total of 15 P/LP variants were found in 34 patients (diagnostic yield: 20.9%): 14 in the LDLR gene and 1 in the APOB gene. Additionally, 24, 54, and 13 VUS were detected in LDLR, APOB, and PCSK9, respectively. No P/LP variants were identified in the other tested genes. Conclusions: Despite the high clinical likelihood of FH, confirmed P/LP variants were detected in only 20.9% of patients in the Latvian cohort when assessed with genome-wide next generation sequencing.This research is funded by the Latvian Council of Science, project “Low-coverage whole-genome sequencing analysis of polygenic mechanisms of high cholesterol levels in patients with clinically diagnosed or possible familial hypercholesterolemia”, project No. lzp-2020/1-0151.info:eu-repo/semantics/publishedVersio

Portuguese Familial Hypercholesterolemia Study (1999-2021): phenotype-genotype characterization

A 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 Hypercholesterolemia (FH) is a common genetic condition of lipid metabolism that is underdiagnosed. There are three primary genes associated with FH (LDLR, APOB and PCSK9) and 5 phenocopy genes (LDLRAP1, LIPA, ABCG5, ABCG8 and APOE), which confer a phenotype FH-like. In this work, we present the phenotype – genotype characterization of individuals with clinical criteria of FH referred to the Portuguese FH Study. Until the end of 2021, 1005 individuals with clinical diagnosis of FH were molecularly studied. Of these, 417 index cases (408 heterozygotes and 9 homozygotes) were genetically confirmed with FH (FH positive). Cascade screening also identified 581 heterozygotes and 2 homozygotes. Among the FH positives, the index cases with null allele variants show a more severe phenotype than the index cases with defective allele variants. About 1% of the index cases were diagnosed with other monogenic causes. Of the FH negatives, 34% have hyper-Lp(a), 18% have a polygenic hypercholesterolemia and 1% have a pathogenic variant in heterozygosity in a FH phenocopy genes. The different genetic causes contribute to a variety of phenotypes that require different forms of disease management, specific therapies and have implications for cardiovascular risk stratification and family screening. Therefore, it is essential that the etiology of hypercholesterolemia is identified as early as possible to improve the prognosis of individuals with FH.info:eu-repo/semantics/publishedVersio

Personalized Medicine in Familial Hypercholesterolemia : diagnosis, stratification of cardiovascular disease risk and lipid therapy management

Familial hypercholesterolemia (FH) is a common lipid metabolism disorder, caused by pathogenic variants in LDLR, APOB and PCSK9. It is characterized by life-long elevated cholesterol concentrations, making it a high cardiovascular disease (CVD) risk condition. Treatment of FH is made primarily with statins, but recently other cholesterol lowering therapies were approved. FH patients present a wide variability in response to statins, which could be caused by type of FH variant and/or genetic variants associated with statin pharmacogenetics. Thus, FH is a perfect model for Personalized Medicine, as patient’s genetic background and additional risk factors can ensure correct diagnosis and guide prevention and treatment options. However, FH is severely underdiagnosed worldwide. Consequently, this work aims at producing evidence to improve FH genetic diagnosis and treatment. A database of all published FH-associated variants was constructed to ensure quick access to data for genetic diagnosis. This was the basis to develop an internationally approved guideline for LDLR variant pathogenicity classification, by joining efforts with an international consortium. With the network of FH experts created, FH variant data publicly available at a reference repository of clinical genetic data increased 10-fold. Specific adaptations for APOB and PCSK9 variant classification were also proposed. To improve CVD prevention, treatment patterns were studied, individual risk factors and overall risk were analyzed in FH patients and in the Portuguese general population. Results showed that four times more FH patients had had CVD events, and although more likely to be medicated, they are less likely to meet recommended target lipid values. Finally, a preliminary study on statin pharmacogenetics yielded some promising results that, if validated in larger studies, could explain variability of response to statins. An accurate diagnosis of FH, precise individual CVD risk stratification and individually adjusted therapy to maximize CVD prevention are the basis of Personalized Medicine in FH

Personalised medicine for Familial Hypercholesterolemia – pilot study

Familial Hypercholesterolemia (FH) confers a high risk for cardiovascular disease (CVD) with several modulating characteristics, which makes it the perfect candidate for personalised medicine approaches.With thanks to the EAS for support in the form of a Young Investigator FellowshipN/

Contribuição para o estabelecimento de uma relação genótipo GJB2/GJB6 VS sucesso do implante coclear em indivíduos surdos da população portuguesa

Tese de mestrado, Biologia (Biologia Molecular e Genética), 2008, Universidade de Lisboa, Faculdade de CiênciasO diagnóstico precoce da surdez é importante para a tomada de decisão relativamente à (re)habilitação dos indivíduos, nomeadamente através do uso de Implante coclear (CI). O diagnóstico molecular de mutações em GJB2 é hoje realizado rotineiramente para estudos etiológicos da surdez, sugerindo alguns estudos anteriores que crianças com surdez associada a GJB2 são bons candidatos a CI. Neste estudo analisou-se o gene GJB2 e duas deleções comuns em GJB6 em 57 indivíduos portugueses com CI há pelo menos 5 anos e investigou-se uma possível associação com o sucesso da (re)habilitação oral. Também foram analisadas duas outras amostras, uma constituída por 94 indivíduos aleatórios de Leiria e do Alentejo, e outra por 22 famílias com NSRD, para estimar a prevalência de mutações em GJB2 neste estudo. Nas amostras de Leiria e do Alentejo encontrámos alterações em GJB2 em 17% e 6.4% dos casos, respectivamente, não havendo diferenças significativas entre estes valores. Não foram encontrados portadores da mutação 35delG. Nas famílias com NSRD 17% dos probandos apresentavam surdez associada a GJB2, sendo 35delG o alelo mutado mais comum (87%). Os indivíduos com CI foram implantados no CHC onde foram avaliados ao nível clínico, audiológico e de desempenho na fala, a fim de estimar o sucesso da sua (re)habilitação oral. Os resultados da análise molecular mostram que quase metade dos indivíduos (42%) tem mutações em GJB2, tendo a causa da surdez ficado estabelecida em 37% dos casos. O alelo mutado mais comum foi 35delG (87%). Nenhuma das deleções em GJB6 foi detectada. Não foi encontrada uma associação significativa entre o sucesso da (re)habilitação oral e a presença/ausência de mutações em GJB2 neste estudo. No entanto, ficou bem evidenciado o papel importante da surdez associada ao gene GJB2 em Portugal e o sucesso da (re)habilitação oral destes indivíduosEarly diagnosis of deafness is important for decision-making concerning (re)habilitation of the individuals, namely through the use of cochlear implant (CI). Molecular diagnosis of GJB2 mutations is now routinely performed for etiological studies of deafness, some previous reports suggesting that children with GJB2-associated hearing loss are good CI candidates. This study analyzed the GJB2 gene and two common deletions in GJB6 in 57 Portuguese individuals with CI for at least 5 years and investigated a possible association with the success of oral (re)habilitation. Two other samples were also analysed, one consisting of 94 random individuals from Leiria and Alentejo, and another of 22 families with NSRD, to estimate the prevalence of GJB2 mutations in this study. In the samples from Leiria and Alentejo GJB2 variants were found in 17% and 6.4% of cases, respectively, with no significant differences between these values. No carriers of the 35delG mutation were found. In the families with NSRD 17% of the probands presented GJB2-associated deafness, 35delG being the most common mutated allele (87%) found. All individuals with CI were implanted in CHC where they were evaluated at clinical, audiological and speech performance level in order to estimate the success of their oral (re)habilitation. The molecular analysis showed that nearly half of individuals (42%) have mutations in GJB2, the cause of deafness having been established in 37% of cases. The most common mutated allele was 35delG (87%). None of the GJB6 deletions was detected. No significant association between the success of oral (re)habilitation and presence/absence of mutations in GJB2 was found in this study. However, it was clearly highlighted the important role of GJB2-associated deafness in Portugal and the success of these individuals' oral (re)habilitatio

Familial hypercholesterolemia [CHAPTER 17]

Translational and Applied Genomics SeriesFamilial hypercholesterolemia (FH) is a common autosomal dominant disorder of lipid metabolism, with a heterozygous frequency of 1/250e1/500 in most of the European countries. Clinically FH is characterized by elevated concentrations of plasma cholesterol that accumulates in arteries and tendons from birth leading to premature coronary heart disease (pCHD). (...)info:eu-repo/semantics/publishedVersio

e_LIPID–Characterization of hypercholesterolemia and association with cardiovascular disease in the Portuguese population

The e_LIPID study aimed to characterise the lipid profile of the Portuguese population and study its association with cardiovascular disease (CV D) events. Demographic, clinical, and biochemical data derived from the e_COR Study, a cross-sectional epidemiological study with 1688 adults (18-79 years old) from five Portuguese continental regions. Population specific percentiles for lipid and lipoprotein biomarkers were esmated stratified by sex and age. All calculations were weighted by sex, age, and geographic region to be representative of the mainland Portuguese population. Odds ratio was calculated to study association of biochemical profile with CV D. Associations of total cholesterol (TC), LDL, ApoB and non-HDL were performed only on individuals under no lipid-lowering therapy. Individuals with LDL above the 9th5 percentile and fulfilling Simon-Broome criteria of Familial Hypercholesterolemia (FH) were sequenced for LDLR, APOB and PCSK9. National prevalence of individuals with TC≥190mg/dl were 52.4%, with LDL≥116mg/dl were 53.9%, with ApoB≥90mg/dl were 53.8%, with non- HDL≥146mg/dl were 38.9%, and with Lp(a)≥125nmol/L were 21.1%. The 90th percentile for lipid and lipoprotein biomarkers for the Portuguese population are TC of 244mg/dl, LDL of 169mg/dl, ApoB of 128mg/dl, non-HDL of 193mg/dl, and Lp(a) of 223nmol/L. The 10th percentile for HDL is 38mg/dl. Individuals with LDL≥116mg/dl presented 2.50 [1.13-6.07] higher odds of having had CV D events (p=0.018), with non-HDL≥146mg/dl had 2.06 [1.01-4.31] higher odds (p=0.041), and with high Lp(a)≥125nmol/L had 1.77 [1.13-2.72] higher odds (p=0.008) than their respective counterparts. From the 33 individuals sequenced 3 individuals were found to have heterozygous FH. Population age and sex specific values are important for dyslipidaemia assessment. Having LDL≥116mg/dl, non-HDL≥146mg/dl or Lp(a) ≥125nmol/L can double the odds of CV D. Our results highlight that hypercholesterolemia is a neglected cardiovascular risk factor with more than 50% of the population with TC≥190mg/dl, LDL≥116mg/dl, or ApoB≥90mg/dl. Since hypercholesterolemia is a modifiable risk factor in the majority of cases, strategies to increase adherence to changes in lifestyle habits need to be urgently discussed.FCTN/