Vera Belova

Background/Objectives: The application of pharmacogenomics (PGx) in pediatrics is limited by the lack of age-oriented interpretation, as adult algorithms do not account for ontogenetic changes in drug-metabolizing enzymes and transport proteins. We aimed to evaluate the clinical applicability of PGx data in Russian children, to assess directional interaction between genotype-based recommendations and enzyme ontogeny, and develop recommendations for age-oriented PGx reporting. Methods: We analyzed whole-exome sequencing data from 524 pediatric patients and 635 newborns. Pharmacogenomic annotations were filtered according to PharmGKB/ClinPGx evidence levels (1A–2B) and the “Pediatrics” tag. In 100 pediatric patients, medical records were retrospectively reviewed for pharmacotherapy and adverse drug reactions (ADRs). An allele-frequency-weighted ADR cost index (AFW-ADR) was calculated for 25 gene–variant–drug–ADR associations (in pediatric cohort), with cost anchors graded by proxy quality. A utilization-weighted variant (AFW-ADR × f_drug) was additionally calculated. Results: Clinically relevant annotations accounted for 5% of initial annotations in both cohorts; 67.6% and 67.2% of these in pediatric and neonatal cohorts, respectively, involved risk alleles with altered function. ADRs occurred in 21% of pediatric patients; only 2/21 cases were explained by high-evidence annotations. Genotype-based recommendations and neonatal enzyme ontogeny were directionally aligned in 5 of 11 assessable gene–drug pairs (45.5%). In the AFW-ADR ranking, the highest values were MTHFR rs1801133–methotrexate toxicity ($22,368), CYP2C9*2/*3–phenytoin SJS/DRESS/TEN ($10,020 and $9540), UGT1A1*28–irinotecan neutropenia ($4658), and HLA-A*31:01–carbamazepine SJS/DRESS/TEN ($3720); however, MTHFR is not clinically actionable. After weighting by pediatric drug utilization, methotrexate remained first, carbamazepine rose to the top ranks, followed by phenytoin, while UGT1A1*28–irinotecan fell to the lowest ranks. This index does not incorporate penetrance and should be interpreted as an exploratory prioritization framework. Conclusions: Age is critical for pediatric PGx interpretation because current reporting approaches do not adequately incorporate ontogeny. We propose an age-oriented PGx model incorporating patient age, ontogenetic adjustment, evidence-level stratification, and multidisciplinary clinical assessment, requiring prospective validation.

Background: Personalized pharmacotherapy requires systematic consideration of genetic factors influencing drug efficacy and safety. The accumulation of large-scale whole-exome sequencing (WES) resources provides an opportunity to assess population frequencies of clinically significant pharmacogenetic variants; however, the applicability of exome-based pharmacogenomics across populations, particularly those underrepresented in existing reference datasets, requires further evaluation. Materials and methods: A retrospective analysis of 6102 anonymized sequencing datasets obtained between 2020 and 2025 was performed using the DNBSEQ-G400 (MGI) platform and Agilent SureSelect Human All Exon v6/v7/v8 enrichment kits. SNV and indel detection, CNV analysis, high-resolution HLA typing, and diplotype assignment for key pharmacogenes were conducted. Pharmacogenomic annotations were derived from ClinPGx (formerly PharmGKB) (levels of evidence 1 A–2B), CPIC, and PharmVar. Haplotype phasing (SHAPEIT5), genotype imputation (IMPUTE5), and phased linkage disequilibrium analysis were performed using a reference panel of 814 Russian whole-genome sequences generated with the same bioinformatic workflow to assess the feasibility of reconstructing clinically relevant non-coding pharmacogenetic variants not captured by WES. Results: WES reliably detected 33 of 34 Very Important Pharmacogenes (VIPs), allowing determination of allele frequencies, metabolizer statuses for 13 VIPs, and HLA diversity. The highest allelic and phenotypic variability was observed in CYP2D6 , CYP2C19 , and CYP2B6 . A total of 663 ClinPGx annotations were identified, predominantly related to drug metabolism (50.38%) and toxicity (29.56%), involving psychotropic drugs, anticoagulants, statins, opioid analgesics, antineoplastic agents, and immunosuppressants. However, at least 32 drugs require assessment of non-coding pharmacogenetic variants or accurate CYP2D6 copy number determination – both beyond standard WES capability. Phased haplotype analysis demonstrated that haplotype-based imputation was feasible for only a limited subset of clinically relevant non-coding pharmacogenetic variants, whereas the majority lacked informative exonic proxies required for accurate inference from WES data. Conclusion: These findings represent one of the largest reference resource to date of pharmacogenetically significant variant and HLA allele frequencies in the Russian population. The results confirm WES as a robust and scalable platform for population-level pharmacogenomic screening and broader clinical genomic applications, while demonstrating that haplotype-based imputation cannot fully overcome the intrinsic limitations of exome sequencing for comprehensive pharmacogenomic profiling. Selection of genomic testing strategies should balance diagnostic completeness, analytical complexity, cost, scalability, and long-term potential for reanalysis.

Introduction: The application of pharmacogenomics (PGx) in pediatrics is limited by the lack of age-oriented interpretation approaches, as algorithms developed for adults do not account for ontogenetic changes in the activity of drug-metabolizing enzymes and transport proteins. The aim of this study was to evaluate the clinical applicability of pharmacogenomic data in Russian children, assess the concordance between genotype-based recommendations and the ontogenetic status of drug-metabolizing enzymes, and develop recommendations for the generation of age-oriented PGx reports. Methods: We analyzed whole-exome sequencing (WES) data from 524 pediatric patients and 635 newborns, filtering pharmacogenomic annotations according to PharmGKB/ClinPGx evidence levels (1A–2B) and the presence of the “Pediatrics” tag. The concordance between genotype-based recommendations and the ontogenetic status of drug-metabolizing enzymes was assessed in newborns. In a pediatric subgroup of 100 patients, a retrospective analysis of medical records was performed to evaluate the structure of pharmacotherapy and the frequency of adverse drug reactions (ADRs). A “PGx–ADR–cost” database was created, and the relative population burden index was calculated for 27 gene–variant–drug–ADR associations. Results: Clinically relevant annotations (requiring drug avoidance or dose modification) accounted for only 5% of all initial pharmacogenomic annotations in both cohorts; 67.6% (pediatric cohort) and 67.2% (neonatal cohort) of these were related to alleles with altered function. Concordance between genotype-based recommendations and the ontogenetic status of drug-metabolizing enzymes in newborns was observed in only 5 of 14 (35.71%) gene–drug pairs. ADRs were identified in 21% of the 100 pediatric patients; however, only two cases could be explained by high-evidence PharmGKB/ClinPGx annotations. Ranking by relative population burden identified UGT1A1*28 –irinotecan-induced neutropenia and HLA-A*31:01 –carbamazepine-induced severe cutaneous reactions as priority associations. Conclusions: Age represents a critical factor in the interpretation of pharmacogenomic data in children, as current approaches to PGx reporting do not adequately incorporate the ontogenetic context. We propose a pediatric PGx interpretation model that includes mandatory reporting of patient age, ontogenetic adjustment, evidence-level stratification, and multidisciplinary clinical assessment. Prospective validation is required to confirm the clinical utility of the proposed approach.

Adverse drug reactions (ADRs) remain a major public health issue, and genetic factors contribute importantly to interindividual variability in drug response. Pharmacogenetic testing helps reduce ADR risk by optimizing drug selection and dosage, particularly in monogenic disorders. Whole-exome sequencing of 6739 samples from the Russian population was performed on the DNBSEQ-G400 platform (MGI). Variants in 48 genes were examined, focusing on inherited arrhythmias, enzyme deficiencies (Glucose-6-Phosphate Dehydrogenase Deficiency [G6PDD], Porphyrias), Dravet Syndrome (DS) and Malignant Hyperthermia (MH). Variants reported as pathogenic (P), likely pathogenic (LP), or variants of uncertain significance (VUS) in ClinVar were manually re-evaluated using ACMG criteria. A total of 75 unique variants in 18 genes were observed in 119 individuals (1.77%), including 21 carriers and 13 women with a G6PD mutation. Of these, 44 variants were classified as P, 24 as LP, and 7 as VUS. Missense variants accounted for the largest proportion (73.33%). The most affected genes were KCNQ1 (24/119), which exhibited the highest number of unique variants (18), G6PD (20/119), SCN1A (15/119), and RYR1 (14/119). Regarding associated conditions, mutations linked to arrhythmias were found in 51 individuals, MH in 27, G6PDD in 20, DS in 15, and Porphyrias in 6. Integrating common and rare clinically actionable genetic variants with attention to penetrance and clinical validity may improve medication safety, reduce preventable ADRs, and enhance personalized pharmacotherapy.

This study evaluates primary template-directed amplification (PTA) for whole exome sequencing (WES) of small fibroblast cell groups, which mimics the limit

Background: Direct oral anticoagulants (DOACs) are first-line medications for stroke prevention in non-valvular atrial fibrillation (AF). However, variability in drug response poses risks of hemorrhagic or thromboembolic events. Objectives: Although genetic influences on DOACs safety are increasingly recognized, robust evidence directly linking specific polymorphisms to bleeding risk remains limited. Design: Multi-center observational case–control study including exome-wide association analysis of 196 non-valvular AF patients treated with rivaroxaban or apixaban, comprising 97 with bleeding complications and 99 without. Methods: DOAC plasma concentrations, urinary 6-β-hydroxycortisol and cortisol levels were measured for CYP3A4 phenotyping. Sequencing was performed on the DNBSEQ G-400 platform. Single-nucleotide variant (SNV) associations with bleeding risk were assessed using logistic regression with additive, dominant, and recessive genetic models. Polygenic risk scores (PRSs) were calculated to evaluate cumulative genetic effects. Results: No SNVs reached Bonferroni-corrected significance under any model. PRSs showed weak predictive ability for bleeding with apixaban. For rivaroxaban, regression indicated that ln C _{ss min} /D + 1 index increased with PRS, age, and 6-β-hydroxycortisol/cortisol ratio, but decreased with higher 6-β-hydroxycortisol and coronary heart disease presence. No statistically significant differences were found for the PharmGKB Level 3 variants rs1045642 (rivaroxaban) and rs2231142 (apixaban). Trends toward statistical significance were observed for the rs2472304-G variant in rivaroxaban users, rs6977165-C in apixaban users, and for the CYP3A4*1/*36 diplotype. Conclusion: Residual equilibrium concentration of DOACs, including dose-adjusted, did not independently predict bleeding risk in non-valvular AF patients. Variants rs2472304 and rs6977165 may warrant further investigation as potential contributors to bleeding risk.

Inherited epidermolysis bullosa (EB) comprises a group of genetic disorders characterized by fragile skin that blisters easily. Targeted therapies for EB necessitate personalized approaches, underscoring the importance of precise diagnostics through genetic analysis and skin biopsy using transmission electron microscopy and/or immunohistochemistry. This study highlights the application of whole-exome sequencing (WES) to identify key pathogenic variants associated with EB. Most identified variants were associated with the recessive form of dystrophic EB, including four novel COL7A1 mutations: p.Leu1488ArgfsTer222, c.7759-3C>G, p.Gln1886Ter, and c.6501+6T>C, as well as recurrent variants p.Lys142Arg and p.Gly2049Glu. Additionally, variants were detected in KRT5 (c.971T>C, p.Val324Ala), associated with EB simplex, and in LAMB3 (c.2500C>T, p.Gln834Ter) in the homozygous state, associated with junctional EB. In silico splice prediction tools suggested disrupted splicing in both cases. One patient received topical gentamicin therapy targeting the nonsense mutation p.Gln1886Ter. These findings underscore the utility of WES in EB diagnostics, broaden the mutation spectrum, and contribute to the understanding of genotype–phenotype correlations in adult patients with EB.

The first Russian human genome standard E701 was developed through a collaborative research involving four laboratories: Pirogov Russian National Research Medical University, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I.Kulakov, National Research Center Kurchatov Institute, and National Medical Research Radiological Centre. Whole-genome sequencing of short reads on various platforms (MGI Tech, Illumina) and alignment to the reference human genome GRCh38.p14 were performed for the E701 sample. Subsequently, 3842 877 genomic variants were identified, which can be used as a standard for calculating statistical quality metrics while analyzing sequencing data. This variant set was additionally filtered by the GIAB high-confidence regions version 4.2.1, yielding 3262 154 variants. Moreover, E701 sample has undergone multiple whole-exome sequencing using five different enrichment panels for exome–genome concordance analysis. Furthermore, 9096 bi-allelic variants were identified on the autosomes and the X chromosome, with a minor allele frequency exceeding 0.4. Additionally, mitochondrial DNA sequencing was performed with the breadth of coverage over 99.9% at 1000×.

Whole exome sequencing (WES) is essential for identifying genetic variants linked to diseases. This study compares available to date four exome enrichment kits: Agilent SureSelect Human All Exon v8, Roche KAPA HyperExome, Vazyme VAHTS Target Capture Core Exome Panel, and Nanodigmbio NEXome Plus Panel v1. We evaluated target design, coverage statistics, and variant calling accuracy across these four different exome capture products. All kits showed high target coverage, with 10x coverage exceeding 97.5% and 20x coverage above 95%. Roche exhibited the most uniform coverage, indicated by the lowest fold-80 scores, while Nanodigmbio had more on-target reads due to fewer off-target reads. Variant calling performance, evaluated using in-lab standard E701 DNA sample, showed high recall rates for all kits, especially Agilent v8. All kits achieved an F-measure above 95.87%. Nanodigmbio had the highest precision with the fewest false positives but a slightly lower F-measure than other kits. This study also highlights the performance of new solutions from Vazyme (China) and Nanodigmbio (China), which were comparable to Agilent v8 and Roche KAPA kits. These findings assist researchers and clinicians in selecting appropriate exome capture solutions.

The certified reference material (CRM) of human genomic DNA composition E701 was developed to provide metrological support for measurements carried out in the study of hereditary genetic diseases, paternity testing, detection of mutations in the human genome, and diagnosis of oncological diseases. To determine its metrological characteristics, approved types of measuring instruments and reference materials were used. The values of the mass concentration of the reference material were obtained by spectrophotometry and real-time PCR. The values of the mass fractions of each nucleotide were obtained by next-generation sequencing (NGS) using DNBSEQ-G400 sequencers and by Illumina high-throughput sequencing using a NovaSeq sequencer. The errors in obtaining the values of the mass fractions and mass concentration of the reference material were evaluated. The relative error of the certified value of the nucleotide mass fractions of the CRM did not exceed 1.5%, and the relative error of the certified value of the mass concentration of human genomic DNA did not exceed 8%. When using high-precision measuring instruments calibrated immediately before measurements, these errors will be even smaller. The developed reference material can be used in healthcare, research, forensic medical and judicial examination, sanitary-epidemiological surveillance, laboratory diagnostics, and for state control (supervision) measures.