The diversity in our genome is crucial to understanding the demographic history of worldwide populations. However, we have yet to know whether subtle genetic differences within a population can be ...disentangled, or whether they have an impact on complex traits. Here we apply dimensionality reduction methods (PCA, t-SNE, PCA-t-SNE, UMAP, and PCA-UMAP) to biobank-derived genomic data of a Japanese population (n = 169,719). Dimensionality reduction reveals fine-scale population structure, conspicuously differentiating adjacent insular subpopulations. We further enluciate the demographic landscape of these Japanese subpopulations using population genetics analyses. Finally, we perform phenome-wide polygenic risk score (PRS) analyses on 67 complex traits. Differences in PRS between the deconvoluted subpopulations are not always concordant with those in the observed phenotypes, suggesting that the PRS differences might reflect biases from the uncorrected structure, in a trait-dependent manner. This study suggests that such an uncorrected structure can be a potential pitfall in the clinical application of PRS.
Obesity is a risk factor for a wide variety of health problems. In a genome-wide association study (GWAS) of body mass index (BMI) in Japanese people (n = 173,430), we found 85 loci significantly ...associated with obesity (P < 5.0 × 10
), of which 51 were previously unknown. We conducted trans-ancestral meta-analyses by integrating these results with the results from a GWAS of Europeans and identified 61 additional new loci. In total, this study identifies 112 novel loci, doubling the number of previously known BMI-associated loci. By annotating associated variants with cell-type-specific regulatory marks, we found enrichment of variants in CD19
cells. We also found significant genetic correlations between BMI and lymphocyte count (P = 6.46 × 10
, r
= 0.18) and between BMI and multiple complex diseases. These findings provide genetic evidence that lymphocytes are relevant to body weight regulation and offer insights into the pathogenesis of obesity.
To understand the genetics of type 2 diabetes in people of Japanese ancestry, we conducted A meta-analysis of four genome-wide association studies (GWAS; 36,614 cases and 155,150 controls of Japanese ...ancestry). We identified 88 type 2 diabetes-associated loci (P < 5.0 × 10
) with 115 independent signals (P < 5.0 × 10
), of which 28 loci with 30 signals were novel. Twenty-eight missense variants were in linkage disequilibrium (r
> 0.6) with the lead variants. Among the 28 missense variants, three previously unreported variants had distinct minor allele frequency (MAF) spectra between people of Japanese and European ancestry (MAF
> 0.05 versus MAF
< 0.01), including missense variants in genes related to pancreatic acinar cells (GP2) and insulin secretion (GLP1R). Transethnic comparisons of the molecular pathways identified from the GWAS results highlight both ethnically shared and heterogeneous effects of a series of pathways on type 2 diabetes (for example, monogenic diabetes and beta cells).
Pathogenic variants in highly penetrant genes are useful for the diagnosis, therapy, and surveillance for hereditary breast cancer. Large-scale studies are needed to inform future testing and variant ...classification processes in Japanese. We performed a case-control association study for variants in coding regions of 11 hereditary breast cancer genes in 7051 unselected breast cancer patients and 11,241 female controls of Japanese ancestry. Here, we identify 244 germline pathogenic variants. Pathogenic variants are found in 5.7% of patients, ranging from 15% in women diagnosed <40 years to 3.2% in patients ≥80 years, with BRCA1/2, explaining two-thirds of pathogenic variants identified at all ages. BRCA1/2, PALB2, and TP53 are significant causative genes. Patients with pathogenic variants in BRCA1/2 or PTEN have significantly younger age at diagnosis. In conclusion, BRCA1/2, PALB2, and TP53 are the major hereditary breast cancer genes, irrespective of age at diagnosis, in Japanese women.
Human height is a representative phenotype to elucidate genetic architecture. However, the majority of large studies have been performed in European population. To investigate the rare and ...low-frequency variants associated with height, we construct a reference panel (N = 3,541) for genotype imputation by integrating the whole-genome sequence data from 1,037 Japanese with that of the 1000 Genomes Project, and perform a genome-wide association study in 191,787 Japanese. We report 573 height-associated variants, including 22 rare and 42 low-frequency variants. These 64 variants explain 1.7% of the phenotypic variance. Furthermore, a gene-based analysis identifies two genes with multiple height-increasing rare and low-frequency nonsynonymous variants (SLC27A3 and CYP26B1; P
< 2.5 × 10
). Our analysis shows a general tendency of the effect sizes of rare variants towards increasing height, which is contrary to findings among Europeans, suggesting that height-associated rare variants are under different selection pressure in Japanese and European populations.
Each transfer RNA (tRNA) is aminoacylated (charged) with a genetic codon-specific amino acid at its 3' end. Charged tRNAs are primarily used for translation, whereas fluctuations in charged tRNA ...fractions are known to reflect cellular response to stress. Here we report the development of individual tRNA-acylation using PCR (i-tRAP), a convenient PCR-based method that can specifically quantify individual tRNA charging ratio. In this i-tRAP method, demethylases remove base methylations which are problematic for reverse transcription reaction, and β-elimination reaction specifically removes the 3' end of adenine residue in uncharged tRNA. Subsequent TaqMan MGB qRT-PCR can distinguish between cDNA of charged tRNA and uncharged tRNA. By using this method, we revealed that the charging ratio of tRNAGln(CUG) was changed in response to amino acid starvation and also the charging ratio of tRNAGln(CUG) in senescent cells was lower than in young cells under starvation conditions. i-tRAP can be applicable to the quantification of charging ratio of various tRNAs, and provides a simple and convenient method for analyzing tRNA charging.
To perform detailed fine-mapping of the major-histocompatibility-complex region, we conducted next-generation sequencing (NGS)-based typing of the 33 human leukocyte antigen (HLA) genes in 1,120 ...individuals of Japanese ancestry, providing a high-resolution allele catalog and linkage-disequilibrium structure of both classical and nonclassical HLA genes. Together with population-specific deep-whole-genome-sequencing data (n = 1,276), we conducted NGS-based HLA, single-nucleotide-variant and indel imputation of large-scale genome-wide-association-study data from 166,190 Japanese individuals. A phenome-wide association study assessing 106 clinical phenotypes identified abundant, significant genotype-phenotype associations across 52 phenotypes. Fine-mapping highlighted multiple association patterns conferring independent risks from classical HLA genes. Region-wide heritability estimates and genetic-correlation network analysis elucidated the polygenic architecture shared across the phenotypes.
While polygenic risk scores (PRSs) are poised to be translated into clinical practice through prediction of inborn health risks
, a strategy to utilize genetics to prioritize modifiable risk factors ...driving heath outcome is warranted
. To this end, we investigated the association of the genetic susceptibility to complex traits with human lifespan in collaboration with three worldwide biobanks (n
= 675,898; BioBank Japan (n = 179,066), UK Biobank (n = 361,194) and FinnGen (n = 135,638)). In contrast to observational studies, in which discerning the cause-and-effect can be difficult, PRSs could help to identify the driver biomarkers affecting human lifespan. A high systolic blood pressure PRS was trans-ethnically associated with a shorter lifespan (hazard ratio = 1.031.02-1.04, P
= 3.9 × 10
) and parental lifespan (hazard ratio = 1.061.06-1.07, P = 2.0 × 10
). The obesity PRS showed distinct effects on lifespan in Japanese and European individuals (P
= 9.5 × 10
for BMI). The causal effect of blood pressure and obesity on lifespan was further supported by Mendelian randomization studies. Beyond genotype-phenotype associations, our trans-biobank study offers a new value of PRSs in prioritization of risk factors that could be potential targets of medical treatment to improve population health.
Previous clinical trials indicate that 10%–25% of patients received genomically matched therapy after comprehensive genomic profiling (CGP) tests. However, the clinical utility of CGP tests has not ...been assessed in clinical practice. We assessed the clinical utility of CGP tests for advanced or metastatic solid tumor and determined the proportion of patients receiving genomically matched therapy among those with common and non‐common cancers. From August 2019 to July 2020, a total of 418 patients had undergone CGP tests, and the results were discussed through the molecular tumor board at our site. The median age of patients was 57 (range: 3–86) years. Colorectal cancer was the most common, with 47 (11%) patients. Actionable genomic alterations (median 3, range: 1–17) were identified in 368 (88.0%) of 418 patients. Druggable genomic alterations were determined in 196 (46.9%) of 418 patients through the molecular tumor board. Genomically matched therapy was administered as the subsequent line of therapy in 51 (12.2%) patients, which is comparable to the proportion we previously reported in a clinical trial (13.4%) (p = 0.6919). The proportion of patients receiving genomically matched therapy was significantly higher among those with common cancers (16.2%) than non‐common cancers (9.4%) (p = 0.0365). Genomically matched therapy after the CGP tests was administered to 12.2% of patients, which is similar to the proportion reported in the previous clinical trials. The clinical utility of CGP tests in patients with common cancers greatly exceeded that in patients with non‐common cancers.
Genomically matched therapy after comprehensive genomic profiling (CGP) tests was administered to 12.2% of patients in clinical practice. We demonstrated the clinical utility of CGP tests in clinical practice, particularly among those with common cancers who received genomically matched therapy more frequently than those with non‐common cancers.
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