Twin Research and Human Genetics最新文献

{"title":"The Overlooked Legacy: Genetic Contributions of the Childless.","authors":"Vergard F Skirbekk, Bernt Bratsberg, Christian M Page, Dana Kristjansson","doi":"10.1017/thg.2025.25","DOIUrl":"https://doi.org/10.1017/thg.2025.25","url":null,"abstract":"<p><p>Childless individuals have historically faced stigma with assumptions that they lack an interest in future generations because they do not directly contribute to genetic lineage. Individuals share approximately half of their genes with siblings, 12.5% with first cousins, and 6.25% with first cousins' children. Norwegian census data (2005-2023), reflecting similar trends to the US, UK, and other European countries, indicates a moderate difference in the number of siblings (Parents: 2.03 [women and men]; Childless: 1.88 [women], 1.94 [men]) and nieces/nephews (Parents: 3.99 [women], 4.03 [men]; Childless: 3.32 [women], 3.42 [men]) for 514,777 women and 532,834 men, respectively. By linking four generations through grandmothers, both childless and childbearing women had a slightly higher number of biological extended family members (Parents: 9.63 cousins with 15.79 children; Childless: 8.66 cousins with 12.22 children). Linking four generations for men, numbers were similar: Parents: 9.68 cousins with 15.91 children, Childless: 8.83 cousins with 12.44 children. Based on the average number of children who are parents, the childless have an average genetic fitness that is 49% of that for parents for the next generation. Both parents and childless individuals have a stake in future generations through their biological extended family.</p>","PeriodicalId":23446,"journal":{"name":"Twin Research and Human Genetics","volume":" ","pages":"1-7"},"PeriodicalIF":1.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144643627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bidirectional Mediation of Cognition by DNA Methylation and Lean Body Mass in Chinese Monozygotic Twins.","authors":"Huihui Li, Tong Wang, Xiaocao Tian, Dongfeng Zhang, Weijing Wang","doi":"10.1017/thg.2025.10014","DOIUrl":"https://doi.org/10.1017/thg.2025.10014","url":null,"abstract":"<p><p>This study explores whether DNA methylation (DNAm) mediates the association between lean body mass (LBM) and cognition, as well as whether LBM mediates the association between DNAm and cognition. Based on the data of 59 monozygotic twin pairs, mediation analyses were performed using causal inference test method and mediation analyses. Average causal mediation effect (ACME), average direct effect (ADE), and total effect (TE) were calculated. Among the CpGs associated with LBM, five located within <i>PDGFRB</i> and <i>RP11</i> genes (ACME: -0.0972-0.0463, |ACME/ADE|: 10.44%-18.30%) negatively mediated the association between LBM and cognition, while one in the <i>PAX2</i> gene (ACME: 0.3510, |ACME/TE|: 11.84%) positively mediated the association. Besides, the methylation risk score (MRS) of <i>RP11</i> gene (ACME: -0.0517, |ACME/ADE|: 10.64%) and MRS of all CpGs (ACME: -0.0511, |ACME/ADE|: 10.53%) negatively mediated the association of LBM with cognition. For another, LBM negatively mediated the association between the DNAm level of one CpG within <i>UBXN6</i> and cognition (ACME: -0.0732, |ACME/TE|: 20.78%), while positively mediated the association between the DNAm level of four CpGs within <i>FOXI2</i> and cognition (ACME: 0.2812-0.4496, |ACME/TE|: 18.15%-27.29%). It was found the DNAm in <i>PDGFRB</i>, <i>RP11</i> and <i>PAX2</i> partially mediates the association between LBM and cognition, and the association between DNAm in <i>UBXN6</i> and <i>FOXI2</i> with cognition is also partially mediated by LBM.</p>","PeriodicalId":23446,"journal":{"name":"Twin Research and Human Genetics","volume":" ","pages":"1-9"},"PeriodicalIF":1.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144627137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Twins of Greece: International Symposium on Twins and Twin-Related Events/Twin Research Reviews: Twins' Neonatal Outcomes; Growth Discordance and Growth Restriction; Twins' Romantic Partners and Alcohol Use/Human Interest Stories: The Paget Twins' Extraordinary Lives; Museum Wing Honors the Lost Rockefeller Twin; Remarkable Conjoined Twins in India; Death of an Australian Sports Icon; A Most Unusual Triplet Birth.","authors":"Nancy L Segal","doi":"10.1017/thg.2025.10012","DOIUrl":"https://doi.org/10.1017/thg.2025.10012","url":null,"abstract":"<p><p>Highlights from the International Symposium on Twins, held at the University of Crete on May 23-24, 2025, are summarized. The symposium, organized by Dr Maria Markodimitraki, Professor in the Department of Preschool Education at the University of Crete, attracted scholars and practitioners from Greece and around the world. Meetings with a pair of reunited monozygotic female twins, and a female twin in search of her sister, also from Greece, are described. This review is followed by summaries of twin research on neonatal outcomes, growth discordance and restriction, and romantic partners and alcohol use. Human interest stories include a book documenting the extraordinary lives of identical twins Celia and Mamaine Paget, a museum wing honoring the lost Rockefeller twin, a remarkable conjoined twinning case in India, the death of an Australian sports icon, and a most unusual triplet birth.</p>","PeriodicalId":23446,"journal":{"name":"Twin Research and Human Genetics","volume":" ","pages":"1-6"},"PeriodicalIF":1.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144627138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the Relationship between Polygenic Scores, Community-Shared Socioeconomic Indicators and Major Depressive Disorder Outcome.","authors":"Dante T Sepulveda, Jackson G Thorp, Penelope A Lind, Nicholas G Martin, Sarah E Medland, Brittany L Mitchell","doi":"10.1017/thg.2025.10011","DOIUrl":"https://doi.org/10.1017/thg.2025.10011","url":null,"abstract":"<p><p>Depression, a leading cause of global disability, arises from a multifaceted combination of genetic and environmental components. This study explores the relationship between major depressive disorder (MDD) polygenic scores (PGS), characteristics and symptoms of depression, and community-shared socioeconomic factors derived from postal code data in a cohort of 12,646 individuals from the Australian Genetics of Depression Study (AGDS). Our findings reveal that people living in areas with relatively higher socioeconomic advantages and education/occupation scores are more likely to report experiencing fewer depressive symptoms during their worst depressive period, as well as fewer number of lifetime episodes. Additionally, participants who reported depression onset later in life tend to currently reside in wealthier areas. Interestingly, no significant interaction between genetic and socioeconomic factors was observed, suggesting their independent contribution to depression outcomes. This research underscores the importance of integrating socioeconomic factors into psychiatric evaluation and care, and points to the critical role of public policy in addressing mental health disparities driven by socioeconomic factors. Future research should aim to further elucidate the causal relationships within these associations and explore the potential for integrated genetic and socioeconomic approaches in mental health interventions.</p>","PeriodicalId":23446,"journal":{"name":"Twin Research and Human Genetics","volume":" ","pages":"1-9"},"PeriodicalIF":1.0,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144584998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heritability of Humor Production Ability - A Twin Study.","authors":"Gil Greengross, Nancy Segal, Stephanie Zellers, Paul Silvia, Claire Steves, Jaakko Kaprio","doi":"10.1017/thg.2025.10010","DOIUrl":"https://doi.org/10.1017/thg.2025.10010","url":null,"abstract":"<p><p>Sense of humor is a universal human trait, enjoyed daily across cultures. However, little is known about the factors that shape individual differences in humor, particularly what contributes to developing a great sense of humor. While previous studies have identified a significant genetic component for various humor attributes, such as humor appreciation and humor styles, no study has looked at the heritability of humor production ability. This study is the first to assess the genetic and environmental influences on humor production ability using a twin study design. Participants included 448 pairs of monozygotic twins and 196 pairs of dizygotic twins (median age 66 years, mostly female) from the Twins UK registry. Twins self-assessed their humor ability, rated the funniness of their co-twin, and completed an objective humor production task by composing funny captions for captionless cartoons. Additionally, they completed a short cognitive ability test and reported their overall health. Findings revealed that self-rated humor ability was influenced by both additive genetic and nonshared environmental factors. In contrast, objective humor production showed no evidence of additive genetic effects. Instead, all individual differences were shaped by shared and nonshared environmental influences, though a small genetic effect cannot be ruled out. These results suggest that humor production may be more complex and difficult to assess than other cognitive abilities. The study also presents intriguing implications for the evolutionary basis of humor.</p>","PeriodicalId":23446,"journal":{"name":"Twin Research and Human Genetics","volume":" ","pages":"1-8"},"PeriodicalIF":1.0,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144576365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Behavioral Genetics and Human Agency: How Selectively Deterministic Theories of Free Will Drive Unwarranted Opposition to Behavioral Genetic Research and Undermine Our Moral and Legal Conventions, Part I.","authors":"Damien Morris","doi":"10.1017/thg.2025.22","DOIUrl":"https://doi.org/10.1017/thg.2025.22","url":null,"abstract":"<p><p>This article argues that a pervasive but confused theory of free will is driving unwarranted resistance to behavioral genetic research and undermining the concept of personal responsibility enshrined in our moral and legal conventions. We call this the theory of 'free-will-by-subtraction'. A particularly explicit version of this theory has been propounded by the psychologist Eric Turkheimer, who has proposed that human agency can be scientifically quantified as the behavioral variation that remains unexplained after known genetic and environmental causes have been accounted for. This theory motivates resistance to research that suggests genetic differences substantially account for differences in human behavior because that is seen to reduce the scope of human freedom. In academic philosophy, free-will-by-subtraction theory corresponds to a position called 'libertarian incompatibilism', which holds that human beings are not responsible for behavior that has extrinsic causes yet maintains that free will nonetheless exists because some fraction of human behavior is self-caused. However, this position is rejected by most professional philosophers. We argue that libertarian incompatibilism is inconsistent with a secular materialist outlook in which <i>all</i> human behavior is understood to have extrinsic causes whether those causes are known to science or not - an outlook Turkheimer shares. We show that Turkheimer sustains this contradiction by adopting an untenable position we call 'epistemic libertarianism', which holds that extrinsic causes of our behavior only infringe on our freedom if we know about them. By contrast, the overwhelming majority of secular materialist philosophers support a position called 'compatibilism', which maintains that free will is compatible with the <i>comprehensive</i> extrinsic causation of human behavior. We show that compatibilism neutralizes the threat that genetic explanation poses to human agency and rescues a generous conception of personal responsibility that aligns with our moral intuitions.</p>","PeriodicalId":23446,"journal":{"name":"Twin Research and Human Genetics","volume":" ","pages":"1-15"},"PeriodicalIF":1.0,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144209643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Umbilical Venous Flow Volume and Fetal Combined Cardiac Output in Twin Pregnancies.","authors":"Sommart Bumrungphuet, Katsusuke Ozawa, Wirada Hansahiranwadee, Jin Muromoto, Seiji Wada, Haruhiko Sago","doi":"10.1017/thg.2025.23","DOIUrl":"https://doi.org/10.1017/thg.2025.23","url":null,"abstract":"<p><p>This study aimed to establish normal reference ranges of combined cardiac output (CCO) and umbilical venous flow volume (UVFV) in twin fetuses at 20 to 28 weeks of gestation and to evaluate the differences between monochorionic and dichorionic twins. CCO and UVFV were prospectively measured by ultrasound at two centers. The following exclusion criteria were applied: age <18 years or >45 years, first hospital visit at >16 weeks of gestation, monochorionic monoamniotic twin pregnancy, fetal structural or chromosomal abnormality, fetal growth restriction, twin-twin transfusion syndrome, twin anemia polycythemia sequence, and severe hypertension or renal disease were excluded. The period was divided into three groups: 20-22 weeks of gestation, 23-25 weeks of gestation, and 26-28 weeks of gestation. The CCO and UVFV were measured at least once during each period. CCO and UVFV were collected from 274 and 269 fetuses and were measured 412 and 424 times, respectively. UVFV and CCO levels increased as gestation progressed. The weight-corrected UVFV (UVFV/kg) and CCO (CCO/kg) remained stable. UVFV and CCO did not differ between monochorionic and dichorionic twin fetuses. The mean ± <i>SD</i> of UVFV/kg and CCO/kg were determined as 127.8 ± 31.8 and 439.4 ± 80.1 mL/kg/min, respectively. The UVFV-to-CCO ratio also remained stable from 20 to 28 weeks of gestation, ranging from 27.7% to 31.8%. The values and ranges of UVFV/kg and mean CCO/kg in twins were similar to those in singletons.</p>","PeriodicalId":23446,"journal":{"name":"Twin Research and Human Genetics","volume":" ","pages":"1-8"},"PeriodicalIF":1.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144014748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Twins' Book Series: Behind Their Popularity and Beyond Their Pages/Twin Research Reviews: Twinning in Low-Income Countries; Oxytocin During Twin Pregnancies; Male-Female Twins and Preeclampsia; Loss of a Twin From the Controversial 1960s New York City Twin Study/Human Interest: Monozygotic Quadruplets Conceived Naturally; Twins of Cleopatra and Mark Antony; Star Basketball Player is a Twin; Twin Stabbed at Track Meet; Another Twin Hostage in Gaza Revealed.","authors":"Nancy L Segal","doi":"10.1017/thg.2025.24","DOIUrl":"https://doi.org/10.1017/thg.2025.24","url":null,"abstract":"<p><p>Twins have been popular figures in many fictional works. A review of two well-known twin-based series, and why they fascinate, is presented. This summary is followed by reviews of twinning in low-income countries, oxytocin administration during twin pregnancies, male-female twins and maternal risk of preeclampsia, and the loss of a twin from the controversial 1960s New York City twin study. The final part of this column covers human interest stories involving twins, specifically a monozygotic quadruplet set conceived naturally, the twins born to Cleopatra and Mark Antony, a star basketball player with a twin brother, a twin stabbed at a track meet, and the revelation of another twin hostage held in Gaza.</p>","PeriodicalId":23446,"journal":{"name":"Twin Research and Human Genetics","volume":" ","pages":"1-5"},"PeriodicalIF":1.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144039734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence that Phenotypic <i>g</i> is Both Formative and Reflective From Four Large Genetically-Informative Samples.","authors":"Michael A Woodley Of Menie, Mateo Peñaherrera-Aguirre, John G R Fuerst","doi":"10.1017/thg.2025.17","DOIUrl":"https://doi.org/10.1017/thg.2025.17","url":null,"abstract":"<p><p>Is general intelligence (<i>g</i>) a reflective construct, representing a latent causal entity underlying subtest performance, or a formative construct, better understood as an aggregate variable shaped by and summarizing variation across subtests? Genetically informative data provide a framework for testing whether a construct is reflective or formative by comparing common pathway and independent pathways structural equation models (SEMs). Previous studies using biometric SEMs have predominantly supported the reflective model, with phenotypic <i>g</i> mediating the effects of additive genetic and environmental influences on lower level abilities. In the current study, four large genetically informed datasets (three from the US and one from the UK) were analyzed to test three competing SEM models - common pathway, independent pathways, and merged - using Confirmatory Factor Analysis (CFA). Genetic <i>g</i> was estimated in each sample as a latent variable derived from polygenic scores indexing educational attainment and cognitive abilities. The models were compared as follows: the common pathway model, consistent with a reflective <i>g</i>, included a direct path from genetic <i>g</i> to phenotypic <i>g</i>; the independent pathways model, consistent with a formative <i>g</i>, featured indirect paths from genetic <i>g</i> to phenotypic <i>g</i> via subtests; and the merged model incorporated both direct and indirect paths. Across all four datasets, the merged model consistently provided the best fit (based on goodness-of-fit and parsimony criteria). Phenotypic <i>g</i> mediated between 31% and 81% of the effects of genetic <i>g</i> on subtests. These findings suggest that <i>g</i> functions as both a reflective and formative entity.</p>","PeriodicalId":23446,"journal":{"name":"Twin Research and Human Genetics","volume":" ","pages":"1-15"},"PeriodicalIF":1.0,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144047437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic Similarity Clustering Using the UK Biobank as a Reference Dataset.","authors":"Ngoc-Quynh Le, Puya Gharahkhani, Stuart MacGregor","doi":"10.1017/thg.2025.15","DOIUrl":"https://doi.org/10.1017/thg.2025.15","url":null,"abstract":"<p><p>Incorporating genetic data from diverse populations is crucial for understanding genetic contributions to diseases and ensuring health equity in healthcare practices. However, existing reference panels either capture a limited number of populations or have small sample sizes. We examine the UK Biobank's performance as a reference for clustering genetically similar individuals. Leveraging data from participants of diverse origins, we aim to improve population representation and mitigate bias caused by the limited number of populations in other reference panels. We combined countries of birth and ethnic backgrounds data fields from the UK Biobank and genetic information to infer genetically similar population labels. A random forest model was then trained on genetic principal components to identify each individual's most genetically similar population. The model's performance was validated using the 1000 Genomes and the CARTaGENE biobank data. We identified more diverse reference populations than present in datasets such as 1000 Genomes, covering 19 populations worldwide. Our model achieved medium to high precision and recall for most labeled populations, although lower rates were observed in closely related groups. For instance, we identified 519 people in CARTaGENE most genetically similar to the Middle Eastern reference sample derived in the UK Biobank (there are no Middle Eastern samples in 1000 Genomes), yielding an 81.1% precision and a 97.0% recall rate compared to demographic-based information. This practical approach of clustering genetically similar individuals utilizing existing biobank data may facilitate downstream analyses, such as genomewide association studies or polygenic risk scores in underrepresented populations in genetic studies.</p>","PeriodicalId":23446,"journal":{"name":"Twin Research and Human Genetics","volume":" ","pages":"1-8"},"PeriodicalIF":1.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144015408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}