Publications by authors named "Shu Tadaka"

Large-scale population cohort studies that collect genomic information are tasked with returning an assessment of genetic risk for hereditary cancers to participants. While several studies have applied to return identified genetic risks to participants, comprehensive surveys of participants' understanding, feelings, and behaviors toward cancer risk remain to be conducted. Here, we report our experience and surveys of returning genetic risks to 100 carriers of pathogenic variants for hereditary cancers identified through whole genome sequencing of 50 000 individuals from the Tohoku Medical Megabank project, a population cohort study.

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Next-generation sequencing (NGS) has become widely available and is routinely used in basic research and clinical practice. The reference genome sequence is an essential resource for NGS analysis, and several population-specific reference genomes have recently been constructed to provide a choice to deal with the vast genetic diversity of human samples. However, resources supporting population-specific references are insufficient, and it is burdensome to perform analysis using these reference genomes.

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  • - The study investigates the link between rare copy number variations (CNVs) in synaptic genes and bipolar disorder (BD) in a Japanese population, using genome hybridization techniques on nearly 2,000 BD patients and 2,760 controls.
  • - Results indicate a strong association between the RNF216 gene and BD, with significant findings also related to postsynaptic membrane components, suggesting these genetic factors contribute to BD risk.
  • - The findings enhance understanding of BD's genetic underpinnings, highlighting the importance of CNVs in gene regions that may influence the disorder's development.
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  • - The enzyme CYP2B6 is crucial for metabolizing drugs like efavirenz and propofol, and genetic variations in the CYP2B6 gene can alter its effectiveness and lead to side effects.
  • - This study examined 29 rare genetic variants of CYP2B6 found in a large Japanese population, showing that some variants significantly reduce enzyme activity.
  • - Researchers used techniques like western blotting and molecular simulations to identify how structural changes in the enzyme affect its function, which could aid in predicting drug metabolism and minimizing adverse effects.
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  • Hereditary spastic paraplegia (HSP) is a neurological condition with various forms, and SPG26 is a more complex type that involves difficulty with movement, cognitive issues, and other neurological symptoms due to mutations in the GM2S gene.
  • This study identified a new genetic variant in a Japanese patient with SPG26, which led to the finding that their cells had impaired ganglioside expression, and laboratory tests confirmed that the variant protein lacked the expected enzyme activity.
  • The research also discovered additional potentially harmful genetic variants through analysis of a population database, underscoring the need for further molecular studies on HSP26-related mutations in Japan.
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Understanding the physiological changes associated with aging and the associated disease risks is essential to establish biomarkers as indicators of biological aging. This study used the NMR-measured plasma metabolome to calculate age-specific metabolite indices. In doing so, the scope of the study was deliberately simplified to capture general trends and insights into age-related changes in metabolic patterns.

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Widely used genotype imputation methods are based on the Li and Stephens model, which assumes that new haplotypes can be represented by modifying existing haplotypes in a reference panel through mutations and recombinations. These methods use genotypes from SNP arrays as inputs to estimate haplotypes that align with the input genotypes by analyzing recombination patterns within a reference panel, and then infer unobserved variants. While these methods require reference panels in an identifiable form, their public use is limited due to privacy and consent concerns.

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  • Modern medicine is shifting towards personalized approaches, emphasizing the importance of multi-omics data to better understand diseases and individual genetic variations across different ethnic groups.
  • Projects like the UK Biobank, All of Us, and the Tohoku Medical Megabank have been collecting vital biological specimens to support personalized medicine initiatives.
  • The jMorp web database, which started in 2015, has been updated to include a broader range of data (metabolome, genome, transcriptome, and metagenome) and improved user accessibility for analyzing the diversity of the Japanese population.
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Cytochrome P450 4F2 (CYP4F2) is an enzyme that is involved in the metabolism of arachidonic acid (AA), vitamin E and K, and xenobiotics including drugs. polymorphism (rs2108622; c.1297G>A; p.

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The drug 5-fluorouracil (5-FU) is the first-choice chemotherapeutic agent against advanced-stage cancers. However, 10% to 30% of treated patients experience grade 3 to 4 toxicity. The deficiency of dihydropyrimidinase (DHPase), which catalyzes the second step of the 5-FU degradation pathway, is correlated with the risk of developing toxicity.

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Disorders of sex development (DSD) comprises a congenital condition in which chromosomal, gonadal, or anatomical sex development is atypical. In this study, we screened for pathogenic variants in 32 genes associated with DSDs and central causes of hypogonadism (CHG) in a whole-genome reference panel including 8380 Japanese individuals constructed by Tohoku Medical Megabank Organization. Candidate pathogenic (P) or likely pathogenic (LP) variants were extracted from the ClinVar, InterVar, and Human Gene Mutation databases.

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  • Long-read sequencing technology enhances the analysis of structural variants (SVs), but requires high-quality genomic DNA for large-scale population studies.
  • The study utilized activated T lymphocytes from a biobank to collect high-molecular-weight genomic DNA and sequenced samples from 333 individuals across 111 family trios, uncovering 74,201 SVs.
  • Results indicated that over 95% of the identified SVs followed Mendelian inheritance patterns and associated with specific clinical traits, providing valuable data for exploring genetics in the Japanese population.
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Dihydropyrimidine dehydrogenase (DPD), encoded by the gene, is the rate-limiting enzyme in 5-fluorouracil (5-FU) degradation. In Caucasians, four risk variants are recognized to be responsible for interindividual variations in the development of 5-FU toxicity. However, these risk variants have not been identified in Asian populations.

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Introduction: Pharmacogenomic (PGx) testing results provide valuable information on drug selection and appropriate dosing, maximization of efficacy, and minimization of adverse effects. Although the number of large-scale, next-generation-sequencing-based PGx studies has recently increased, little is known about the risks and benefits of returning PGx results to ostensibly healthy individuals in research settings.

Methods: Single-nucleotide variants of three actionable PGx genes, namely, , , and , were returned to 161 participants in a population-based Tohoku Medical Megabank project.

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To reveal gene-environment interactions underlying common diseases and estimate the risk for common diseases, the Tohoku Medical Megabank (TMM) project has conducted prospective cohort studies and genomic and multiomics analyses. To establish an integrated biobank, we developed an integrated database called "dbTMM" that incorporates both the individual cohort/clinical data and the genome/multiomics data of 157,191 participants in the Tohoku Medical Megabank project. To our knowledge, dbTMM is the first database to store individual whole-genome data on a variant-by-variant basis as well as cohort/clinical data for over one hundred thousand participants in a prospective cohort study.

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Lung function reflects the ability of the respiratory system and is utilized for the assessment of respiratory diseases. Because type 2 airway inflammation influences lung function, genome wide association studies (GWAS) for lung function would be improved by adjustment with an indicator of the inflammation. Here, we performed a GWAS for lung function with adjustment for exhaled nitric oxide (FeNO) levels in two independent Japanese populations.

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Metabolic profiling is an omics approach that can be used to observe phenotypic changes, making it particularly attractive for biomarker discovery. Although several candidate metabolites biomarkers for disease expression have been identified in recent clinical studies, the reference values of healthy subjects have not been established. In particular, the accuracy of concentrations measured by mass spectrometry (MS) is unclear.

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Cytochrome P450 1A2 (CYP1A2), which accounts for approximately 13% of the total hepatic cytochrome content, catalyzes the metabolic reactions of approximately 9% of frequently used drugs, including theophylline and olanzapine. Substantial inter-individual differences in enzymatic activity have been observed among patients, which could be caused by genetic polymorphisms. Therefore, we functionally characterized 21 novel CYP1A2 variants identified in 4773 Japanese individuals by determining the kinetic parameters of phenacetin -deethylation.

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Ethnic-specific SNP arrays are becoming more important to increase the power of genome-wide association studies in diverse population. In the Tohoku Medical Megabank Project, we have been developing a series of Japonica Arrays (JPA) for genotyping participants based on reference panels constructed from whole-genome sequence data of the Japanese population. Here, we designed a novel version of the SNP array for the Japanese population, called Japonica Array NEO (JPA NEO), comprising a total of 666,883 markers.

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Cytochrome P450 2C9 (CYP2C9) is an important drug-metabolizing enzyme that contributes to the metabolism of approximately 15% of clinically used drugs, including warfarin, which is known for its narrow therapeutic window. Interindividual differences in CYP2C9 enzymatic activity caused by genetic polymorphisms lead to inconsistent treatment responses in patients. Thus, in this study, we characterized the functional differences in CYP2C9 wild-type (CYP2C9.

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Bone dysplasias are a group of rare hereditary diseases, with up to 436 disease types. Perinatal diagnosis is clinically important for adequate personalized management and counseling. There are no reports focused on pathogenic variants of bone dysplasias in the general population.

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The complete human genome sequence is used as a reference for next-generation sequencing analyses. However, some ethnic ancestries are under-represented in the reference genome (e.g.

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Identification of the population frequencies of definitely pathogenic germline variants in two major hereditary breast and ovarian cancer syndrome (HBOC) genes, BRCA1/2, is essential to estimate the number of HBOC patients. In addition, the identification of moderately penetrant HBOC gene variants that contribute to increasing the risk of breast and ovarian cancers in a population is critical to establish personalized health care. A prospective cohort subjected to genome analysis can provide both sets of information.

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CYP3A4 is among the most abundant liver and intestinal drug-metabolizing cytochrome P450 enzymes, contributing to the metabolism of more than 30% of clinically used drugs. Therefore, interindividual variability in CYP3A4 activity is a frequent cause of reduced drug efficacy and adverse effects. In this study, we characterized wild-type CYP3A4 and 40 CYP3A4 variants, including 11 new variants, detected among 4773 Japanese individuals by assessing CYP3A4 enzymatic activities for two representative substrates (midazolam and testosterone).

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