Východiska: Karcinom prsu je komplexní, multifaktoriální onemocnění, na jehož vzniku se podílejí i genetické faktory. Kromě relativně vzácných patogenních variant ve vysoce či středně penetrantních nádorových predispozičních genech ovlivňují riziko vzniku karcinomu prsu i početné nízce penetrantní alely, které vnímáme jako faktory polygenní dědičnosti. Nízce penetrantní alely mají samostatně zanedbatelný význam, avšak jejich kumulativní účinek může dosáhnout klinicky významných hodnot a lze jej vyjádřit pomocí skóre polygenního rizika (polygenic risk score – PRS), které se v současnosti zvažuje jako možný nástroj pro přesnější odhad absolutního a kumulativního rizika onkologického onemocnění u konkrétní osoby. Cíl: V zahraničí již bylo vyvinuto několik setů pro jednonukleotidový polymorfizmus (single nucleotide polymorphism – SNP) pro stanovení PRS za účelem využití metody v individualizaci rizika v klinické praxi. Následující text si klade za cíl osvětlit základy stanovení PRS a jeho interpretaci jako možného predikčního nástroje. Využití PRS by však mělo být vždy podmíněno genetickým vyšetřením patogenních variant v nádorových predispozičních genech.

Background: Breast cancer is a complex, multifactorial disease influenced by many genetic factors. Besides the relatively rare pathogenic variants in high or moderate penetrant cancer predisposition genes, breast cancer risk is modified by numerous low risk alleles considered to be polygenic genetic factors. While the risks associated with individual polygenic loci are negligible, its cumulative effect can reach clinically significant values and it can be expressed as a polygenic risk score (PRS). PRS is recently considered to be a possible tool improving assessment of absolute and cumulative risks at the individual level. Purpose: Several single nucleotide polymorphism sets for PRS assessment have recently been developed and prepared for their implementation into clinical practice. The following text aims to explain the fundamental principles of the PRS assessment and its interpretation as a candidate prediction tool. The use of the PRS should always depend on genetic analysis of pathogenic variants in cancer predisposition genes including its current limitations.

• Klíčová slova
• polygenní dědičnost karcinomu prsu, sporadický karcinom prsu,
• MeSH
• genetická predispozice k nemoci MeSH
• lidé MeSH
• multifaktoriální dědičnost MeSH
• nádory prsu * etiologie   genetika   MeSH
• rizikové faktory MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• přehledy MeSH

Prague hereditary hypercholesterolemic (PHHC) rat - rat strain crossbred from Wistar rats - is a model of hypercholesterolemia induced by dietary cholesterol. Importantly, no bile salts and/or antithyroid drugs need to be added to the diet together with cholesterol to induce hypercholesterolemia. PHHC rats have only modestly increased cholesterolemia when fed a standard chow and develop hypercholesterolemia exceeding 5 mmol/l on 2 % cholesterol diet. Most of the cholesterol in hypercholesterolemic PHHC rats is found in VLDL that become enriched with cholesterol (VLDL-C/VLDL-TG ratio > 1.0). Concurrently, both IDL and LDL concentrations rise without any increase in HDL. PHHC rats do not markedly differ from Wistar rats in the activities of enzymes involved in intravascular remodelation of lipoproteins (lipoprotein and hepatic lipases and lecithin:cholesterol acyltransferase), LDL catabolism, cholesterol turnover rate and absorption of dietary cholesterol. The feeding rats with cholesterol diet results in development of fatty liver in spite of suppression of cholesterol synthesis. However, even though cholesterolemia in PHHC rats is comparable to human hypercholesterolemia, the PHHC rats do not develop atherosclerosis even after 6 months on 2 % cholesterol diet. Importantly, the crossbreeding experiments documented that hypercholesterolemia of PHHC rats is polygenic. To identify the genes that may be involved in pathogenesis of hypercholesterolemia in this strain, the studies of microarray gene expression in the liver of PHHC rats are currently in progress.

• MeSH
• ateroskleróza genetika   metabolismus   patologie   MeSH
• cholesterol dietní škodlivé účinky   MeSH
• cholesterol krev   MeSH
• fenotyp MeSH
• financování organizované MeSH
• genetická predispozice k nemoci MeSH
• hybridizace genetická MeSH
• hypercholesterolemie genetika   krev   patologie   MeSH
• játra metabolismus   patologie   MeSH
• krysa rodu rattus MeSH
• lipoproteiny krev   MeSH
• modely nemocí na zvířatech MeSH
• multifaktoriální dědičnost MeSH
• potkani Wistar MeSH
• progrese nemoci MeSH
• ztučnělá játra genetika   metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• přehledy MeSH

The current study focused on longitudinal effects of genetics and parental behaviors and their interplay on externalizing behaviors in a panel study following individuals from adolescence to young adulthood. The nationally representative sample of Add Health participants of European ancestry included N = 4142 individuals, measured on three occasions. Parenting was operationalized as experiences with child maltreatment and maternal closeness. Externalizing problems were operationalized as alcohol use, cannabis use, and antisocial behaviors. Genetic effects were operationalized as a polygenic score (PGS) of risky behaviors. The results showed significant effects for child maltreatment, maternal closeness, and PGS, above and beyond other factors and previous levels of externalizing behaviors. Furthermore, maternal closeness was found to negatively correlate with PGS. No significant interaction effects of parenting and PGS were found. The results underscore the joint independent effects of parenting and genetics on the change in externalizing behaviors from adolescence to young adulthood.

• MeSH
• asociální osobnost genetika   MeSH
• chování mladistvých * MeSH
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• longitudinální studie MeSH
• mladiství MeSH
• mladý dospělý MeSH
• multifaktoriální dědičnost genetika   MeSH
• riskování MeSH
• rodičovství * MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, N.I.H., Extramural MeSH

OBJECTIVES: Bipolar disorder (BD) with early disease onset is associated with an unfavorable clinical outcome and constitutes a clinically and biologically homogenous subgroup within the heterogeneous BD spectrum. Previous studies have found an accumulation of early age at onset (AAO) in BD families and have therefore hypothesized that there is a larger genetic contribution to the early-onset cases than to late onset BD. To investigate the genetic background of this subphenotype, we evaluated whether an increased polygenic burden of BD- and schizophrenia (SCZ)-associated risk variants is associated with an earlier AAO in BD patients. METHODS: A total of 1995 BD type 1 patients from the Consortium of Lithium Genetics (ConLiGen), PsyCourse and Bonn-Mannheim samples were genotyped and their BD and SCZ polygenic risk scores (PRSs) were calculated using the summary statistics of the Psychiatric Genomics Consortium as a training data set. AAO was either separated into onset groups of clinical interest (childhood and adolescence [≤18 years] vs adulthood [>18 years]) or considered as a continuous measure. The associations between BD- and SCZ-PRSs and AAO were evaluated with regression models. RESULTS: BD- and SCZ-PRSs were not significantly associated with age at disease onset. Results remained the same when analyses were stratified by site of recruitment. CONCLUSIONS: The current study is the largest conducted so far to investigate the association between the cumulative BD and SCZ polygenic risk and AAO in BD patients. The reported negative results suggest that such a polygenic influence, if there is any, is not large, and highlight the importance of conducting further, larger scale studies to obtain more information on the genetic architecture of this clinically relevant phenotype.

• MeSH
• bipolární porucha genetika   MeSH
• dítě MeSH
• dospělí MeSH
• fenotyp MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• multifaktoriální dědičnost MeSH
• schizofrenie genetika   MeSH
• věkové faktory MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH

Polygenetic Risk Scores are used to evaluate an individual's vulnerability to developing specific diseases or conditions based on their genetic composition, by taking into account numerous genetic variations. This article provides an overview of the concept of Polygenic Risk Scores (PRS). We elucidate the historical advancements of PRS, their advantages and shortcomings in comparison with other predictive methods, and discuss their conceptual limitations in light of the complexity of biological systems. Furthermore, we provide a survey of published tools for computing PRS and associated resources. The various tools and software packages are categorized based on their technical utility for users or prospective developers. Understanding the array of available tools and their limitations is crucial for accurately assessing and predicting disease risks, facilitating early interventions, and guiding personalized healthcare decisions. Additionally, we also identify potential new avenues for future bioinformatic analyzes and advancements related to PRS.

• MeSH
• celogenomová asociační studie metody   MeSH
• genetická predispozice k nemoci * MeSH
• genetické rizikové skóre MeSH
• hodnocení rizik metody   MeSH
• lidé MeSH
• multifaktoriální dědičnost * MeSH
• rizikové faktory MeSH
• software * MeSH
• výpočetní biologie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

IMPORTANCE: About 20% to 30% of people with schizophrenia have psychotic symptoms that do not respond adequately to first-line antipsychotic treatment. This clinical presentation, chronic and highly disabling, is known as treatment-resistant schizophrenia (TRS). The causes of treatment resistance and their relationships with causes underlying schizophrenia are largely unknown. Adequately powered genetic studies of TRS are scarce because of the difficulty in collecting data from well-characterized TRS cohorts. OBJECTIVE: To examine the genetic architecture of TRS through the reassessment of genetic data from schizophrenia studies and its validation in carefully ascertained clinical samples. DESIGN, SETTING, AND PARTICIPANTS: Two case-control genome-wide association studies (GWASs) of schizophrenia were performed in which the case samples were defined as individuals with TRS (n = 10 501) and individuals with non-TRS (n = 20 325). The differences in effect sizes for allelic associations were then determined between both studies, the reasoning being such differences reflect treatment resistance instead of schizophrenia. Genotype data were retrieved from the CLOZUK and Psychiatric Genomics Consortium (PGC) schizophrenia studies. The output was validated using polygenic risk score (PRS) profiling of 2 independent schizophrenia cohorts with TRS and non-TRS: a prevalence sample with 817 individuals (Cardiff Cognition in Schizophrenia [CardiffCOGS]) and an incidence sample with 563 individuals (Genetics Workstream of the Schizophrenia Treatment Resistance and Therapeutic Advances [STRATA-G]). MAIN OUTCOMES AND MEASURES: GWAS of treatment resistance in schizophrenia. The results of the GWAS were compared with complex polygenic traits through a genetic correlation approach and were used for PRS analysis on the independent validation cohorts using the same TRS definition. RESULTS: The study included a total of 85 490 participants (48 635 [56.9%] male) in its GWAS stage and 1380 participants (859 [62.2%] male) in its PRS validation stage. Treatment resistance in schizophrenia emerged as a polygenic trait with detectable heritability (1% to 4%), and several traits related to intelligence and cognition were found to be genetically correlated with it (genetic correlation, 0.41-0.69). PRS analysis in the CardiffCOGS prevalence sample showed a positive association between TRS and a history of taking clozapine (r2 = 2.03%; P = .001), which was replicated in the STRATA-G incidence sample (r2 = 1.09%; P = .04). CONCLUSIONS AND RELEVANCE: In this GWAS, common genetic variants were differentially associated with TRS, and these associations may have been obscured through the amalgamation of large GWAS samples in previous studies of broadly defined schizophrenia. Findings of this study suggest the validity of meta-analytic approaches for studies on patient outcomes, including treatment resistance.

• MeSH
• celogenomová asociační studie MeSH
• genetická predispozice k nemoci genetika   MeSH
• lidé MeSH
• multifaktoriální dědičnost genetika   MeSH
• psychotické poruchy * farmakoterapie   MeSH
• schizofrenie * diagnóza   farmakoterapie   genetika   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

BACKGROUND: Most cases of pancreatic ductal adenocarcinoma (PDAC) are asymptomatic in early stages, and the disease is typically diagnosed in advanced phases, resulting in very high mortality. Tools to identify individuals at high risk of developing PDAC would be useful to improve chances of early detection. OBJECTIVE: We generated a polygenic risk score (PRS) for PDAC risk prediction, combining the effect of known risk SNPs, and carried out an exploratory analysis of a multifactorial score. METHODS: We tested the associations of the individual known risk SNPs on up to 2851 PDAC cases and 4810 controls of European origin from the PANcreatic Disease ReseArch (PANDoRA) consortium. Thirty risk SNPs were included in a PRS, which was computed on the subset of subjects that had 100% call rate, consisting of 839 cases and 2040 controls in PANDoRA and 6420 cases and 4889 controls from the previously published Pancreatic Cancer Cohort Consortium I-III and Pancreatic Cancer Case-Control Consortium genome-wide association studies. Additional exploratory multifactorial scores were constructed by complementing the genetic score with smoking and diabetes. RESULTS: The scores were associated with increased PDAC risk and reached high statistical significance (OR=2.70, 95% CI 1.99 to 3.68, p=2.54×10-10 highest vs lowest quintile of the weighted PRS, and OR=14.37, 95% CI 5.57 to 37.09, p=3.64×10-8, highest vs lowest quintile of the weighted multifactorial score). CONCLUSION: We found a highly significant association between a PRS and PDAC risk, which explains more than individual SNPs and is a step forward in the direction of the construction of a tool for risk stratification in the population.

• MeSH
• ABO systém krevních skupin genetika   MeSH
• alely MeSH
• časná detekce nádoru MeSH
• duktální karcinom slinivky břišní diagnóza   genetika   MeSH
• frekvence genu MeSH
• hodnocení rizik MeSH
• jednonukleotidový polymorfismus MeSH
• lidé MeSH
• multifaktoriální dědičnost * MeSH
• nádory slinivky břišní genetika   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: The polygenic risk score (PRS) allows the quantification of the polygenic effect of many low-penetrance alleles on the risk of breast cancer (BC). This study aimed to evaluate the performance of two sets comprising 77 or 313 low-penetrance loci (PRS77 and PRS313) in patients with BC in the Czech population. METHODS: In a retrospective case-control study, variants were genotyped from both the PRS77 and PRS313 sets in 1329 patients with BC and 1324 noncancer controls, all women without germline pathogenic variants in BC predisposition genes. Odds ratios (ORs) were calculated according to the categorical PRS in individual deciles. Weighted Cox regression analysis was used to estimate the hazard ratio (HR) per standard deviation (SD) increase in PRS. RESULTS: The distributions of standardized PRSs in patients and controls were significantly different (p < 2.2 × 10-16) with both sets. PRS313 outperformed PRS77 in categorical and continuous PRS analyses. For patients in the highest 2.5% of PRS313, the risk reached an OR of 3.05 (95% CI, 1.66-5.89; p = 1.76 × 10-4). The continuous risk was estimated as an HRper SD of 1.64 (95% CI, 1.49-1.81; p < 2.0 × 10-16), which resulted in an absolute risk of 21.03% at age 80 years for individuals in the 95th percentile of PRS313. Discordant categorization into PRS deciles was observed in 248 individuals (9.3%). CONCLUSIONS: Both PRS77 and PRS313 are able to stratify individuals according to their BC risk in the Czech population. PRS313 shows better discriminatory ability. The results support the potential clinical utility of using PRS313 in individualized BC risk prediction.

• MeSH
• dospělí MeSH
• genetická predispozice k nemoci * MeSH
• genetické rizikové skóre MeSH
• hodnocení rizik metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• multifaktoriální dědičnost genetika   MeSH
• nádory prsu * genetika   MeSH
• retrospektivní studie MeSH
• rizikové faktory MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Geografické názvy
• Česká republika MeSH

• MeSH
• celogenomová asociační studie MeSH
• duševní poruchy * genetika   MeSH
• fenotyp * MeSH
• genetická predispozice k nemoci genetika   MeSH
• lidé MeSH
• multifaktoriální dědičnost * genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• úvodníky MeSH

Accurate colorectal cancer (CRC) risk prediction models are critical for identifying individuals at low and high risk of developing CRC, as they can then be offered targeted screening and interventions to address their risks of developing disease (if they are in a high-risk group) and avoid unnecessary screening and interventions (if they are in a low-risk group). As it is likely that thousands of genetic variants contribute to CRC risk, it is clinically important to investigate whether these genetic variants can be used jointly for CRC risk prediction. In this paper, we derived and compared different approaches to generating predictive polygenic risk scores (PRS) from genome-wide association studies (GWASs) including 55,105 CRC-affected case subjects and 65,079 control subjects of European ancestry. We built the PRS in three ways, using (1) 140 previously identified and validated CRC loci; (2) SNP selection based on linkage disequilibrium (LD) clumping followed by machine-learning approaches; and (3) LDpred, a Bayesian approach for genome-wide risk prediction. We tested the PRS in an independent cohort of 101,987 individuals with 1,699 CRC-affected case subjects. The discriminatory accuracy, calculated by the age- and sex-adjusted area under the receiver operating characteristics curve (AUC), was highest for the LDpred-derived PRS (AUC = 0.654) including nearly 1.2 M genetic variants (the proportion of causal genetic variants for CRC assumed to be 0.003), whereas the PRS of the 140 known variants identified from GWASs had the lowest AUC (AUC = 0.629). Based on the LDpred-derived PRS, we are able to identify 30% of individuals without a family history as having risk for CRC similar to those with a family history of CRC, whereas the PRS based on known GWAS variants identified only top 10% as having a similar relative risk. About 90% of these individuals have no family history and would have been considered average risk under current screening guidelines, but might benefit from earlier screening. The developed PRS offers a way for risk-stratified CRC screening and other targeted interventions.

• MeSH
• Asijci genetika   MeSH
• Bayesova věta MeSH
• celogenomová asociační studie MeSH
• genetická predispozice k nemoci * MeSH
• genom lidský genetika   MeSH
• hodnocení rizik * MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• kolorektální nádory epidemiologie   genetika   patologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• multifaktoriální dědičnost genetika   MeSH
• rizikové faktory MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH