Twin Research and Human Genetics最新文献

This present study investigated the parental characteristics of multiple births using national birth data in Japan. This study included birth data from Vital Statistics: Occupational and Industrial Aspects every five fiscal years from 1995 to 2020. The multiple birth rates were defined as the number of live-birth deliveries with multiple fetuses (e.g., twins, triplets) per total live-birth deliveries. Parental ages, nationalities, occupations and household occupation (occupation of the top earner of the household) were considered as parental characteristics. The multiple birth rates were calculated based on parental characteristics for each year, and a log-binomial regression model was used to assess the association between parental characteristics and multiple births. The multiple birth rate for Japanese mothers consistently exceeded that for non-Japanese mothers over the years, and the rate increased progressively from manual workers to lower non-manual workers and then to upper non-manual workers for both maternal and paternal occupations. The regression results indicated that the risk ratio (RR) for multiple births among non-Japanese mothers was significantly lower than that among Japanese mothers. Moreover, concerning household occupation, the RRs of self-employed individuals, full-time employees at smaller companies, others, and the unemployed were significantly lower than those of full-time employees at larger companies. Furthermore, the RRs of lower non-manual and manual workers were significantly lower than those of upper non-manual workers in maternal and paternal occupations. The results suggested an association between multiple births and parental socioeconomic status in Japan.

Social support is often considered an environmental factor affecting health, especially in aging populations. However, its genetic underpinnings suggest a more complex origin. This study investigates the heritability of social support through applying a threshold model on data of a large adult sample of twins (N = 8019) from the Netherlands Twin Register, collected between 2009 and 2011. The study employed the Duke - UNC Functional Social Support Questionnaire to assess social support quality. Our analysis revealed genetic contributions to social support, with heritability estimated at 37%, without a contribution of shared environment and no differences between men and women in heritability. The study's results underscore the complexity of social support as a trait influenced by genetic and environmental factors, challenging the notion that it is solely an environmental construct.

Voice production can be influenced by interindividual variations related to genetic, physiological, behavioral, and several environmental factors. Here we examined the effect of zygosity on speaking fundamental frequency (F0) statistical descriptors. Our aims were: (1) to determine whether the genetic similarity between monozygotic (MZ) and dizygotic (DZ) twins affects F0 characteristics, and (2) to quantify the contribution of genetic factors to these characteristics. The study involved 79 same-sex twin pairs of Brazilian Portuguese speakers, comprising 65 MZ and 14 DZ twins, aged 18 to 66 years (31.7 ± 11.6 years), with 21 male and 58 female pairs. Participants were recorded while uttering a greeting phrase and the Brazilian Portuguese version of the 'Happy Birthday to You' song. Speech segments were analyzed using Praat free software, and F0 measures were automatically extracted in both Hertz and semitone scales. Statistical descriptors, including centrality, dispersion, and extreme values of F0 were examined, and the ACE model (i.e., total genetic effects, A; shared environmental influences, C; and nonshared environmental influences, E) was employed to estimate the additive effect;ts of monozygosity. As anticipated, we observed a zygosity effect on several F0 parameters, with more similarity between MZ twins compared to DZ twins. We discuss the genetic influences on F0 parameters and the absence of a monozygosity effect in two of them. Additionally, we briefly address potential biases associated with the selected measurement scale for statistical modeling. Finally, we explore the influence of genetic factors on F0 patterns, as well as environmental, life history and linguistic factors, particularly concerning F0 variation in speech.

As with many other musical traits, the social environment is a key influence on the development of singing ability. While the familial singing environment is likely to be formative, its role relative to other environmental influences such as training is unclear. We used structural equation modeling to test relationships among demographic characteristics, familial environmental variables (early and current singing with family), vocal training, and singing ability in a large, previously documented sample of Australian twins (N = 1163). Notably, early singing with family, and to a lesser extent vocal training, predicted singing ability, whereas current singing with family did not. Early familial singing also mediated the relationship between sex and singing ability, with men who sang less with family during childhood showing poorer ability. Bivariate twin models between early familial singing and singing ability showed the phenotypic correlation was largely explained by shared environmental influences. This raises the possibility of a sensitive period for singing ability, with sociocultural expectations around singing potentially differentiating the developmental trajectories of this skill for men and women.

The global rise in twinning rates poses health challenges due to increased risks for infants and mothers. Despite the benefits, breastfeeding rates among multiples are low, with exclusive breastfeeding (EBF) particularly scarce compared to singletons. Our study focuses on the mothers of twins in a unique population in Kodinhi village, Kerala, India, known for its high twinning rates, which aims to contribute to existing knowledge of breastfeeding practices and perspectives in a high twinning environment and offer valuable insights to promote optimal breastfeeding among mothers of twins. A retrospective cross-sectional survey was adopted. Seventy-five mothers with twins under 3 years of age from Kodinhi and neighboring areas were interviewed face to face using structured validated tools. Data collection focused on quantitative data supplemented by narrative descriptions. Most women delivered preterm (57.3%), operative delivery (58.7%), and had a late initiation of breastfeeding (32.9% within 24 hours). Colostrum feed was common (86.7%). The EBF rate was 4%, with 47.9% initiating nonexclusive breastfeeding before 3 months, and most of the twins (46.6%) were breastfed for 1-2 years. Fatigue (69.9%) and low milk supply (38.7%) were chief concerns. While 16.4% of mothers opted for a tandem breastfeeding technique, many preferred consecutive feeding as tandem was challenging. Mothers in Kodinhi demonstrated commendable efforts in breastfeeding twins; despite the low rate of EBF, breastfeeding extended to 1-2 years. Evidence-based interventions and personalized support, primarily focusing on maternal perspectives of milk insufficiency, fatigue and breastfeeding techniques, are crucial for sustaining optimal breastfeeding practices among mothers of twins.

Although there is evidence that social status has a genetic basis, it is less known whether the genetic predisposition differs between men and women as well as among different status indicators and whether there are any intercorrelations among predispositions of status indicators. We therefore investigated the genetic predisposition for different indicators of social status separately for men and women, using polygenic scores obtained from the Wisconsin Longitudinal Study. We used multivariate polygenic regression of 7 different social status indicators on a total of 24 different polygenic scores. We find that in both men and women, wages and education show more associations with polygenic scores than the other status indicators. Also, the genetic predispositions for education and wages are correlated in both men and women, whereas in men more than in women, the genetic predispositions seem to cluster into wages and education on the one hand, and status indicators of position in the hierarchy, on the other hand, with being in a management position somewhere in between. These findings are consistent with an assumption of two different forms of selection pressure associated with either cognitive skill or dominance, which holds true particularly in men. We conclude that the genetic predisposition to higher social status may have changed even though the importance of the cultural trait of social status may have been very constant. Social status may thus be an example of a social trait of constant importance, but with a changing genetic predisposition.

Previous studies have shown that mothers of naturally conceived dizygotic (DZ) twins tend to be taller, older, and smoke more than mothers of naturally conceived monozygotic (MZ) twin and mothers of singletons. Here, we investigate whether mothers of naturally conceived DZ twins differ from mothers who conceived their DZ twins after medically assisted reproduction (MAR) in eight maternal traits related to fertility based on observational survey data. We include data from 33,648 mothers from the Netherlands Twin Register (NTR) and 1660 mothers of twins from the Norwegian Mother, Father and Child Cohort Study (MoBA). We contrast mothers of naturally conceived DZ twins with mothers of MAR DZ twins. Next, we further segment the MAR group into mothers who underwent hormonal induction of ovulation but not in vitro fertilization (IVF) and those who IVF twins, comparing them both to each other and against the mothers of naturally conceived DZ twins. Mothers of naturally conceived DZ twins smoke more often, differ in body composition, have a higher maternal age and have more offspring before the twins than mothers of MZ twins. Compared to MAR DZ twin mothers, mothers of naturally conceived DZ twins have fewer miscarriages, lower maternal age and increased height, more offspring and are more often smokers. BMI before the twin pregnancy is similar in both natural and MAR DZ twin mothers. Mothers who received hormonal induction of ovulation (OI) have a lower maternal age, fewer miscarriages, and a higher number of offspring before their twin pregnancy than twin mothers who received IVF and/or intracytoplasmic sperm injection (ICSI) treatments. Our study shows that twin mothers are a heterogenous group and the differences between twin mothers should be taken into account in epidemiological and genetic research that includes twins.

Immunity activation and inflammation are the main characteristics of rheumatoid arthritis and clonal hematopoiesis. However, it remains unclear whether rheumatoid arthritis increase the risk of clonal hematopoiesis. Here, a Mendelian randomization (MR) analysis was conduct to explore the causal effects of rheumatoid arthritis on clonal hematopoiesis. Summary statistics data of rheumatoid arthritis (13,838 cases and 33,742 controls) and clonal hematopoiesis (10,203 cases and 173,918 controls) derived from a genomewide association study were selected to analyze. We selected inverse-variance weighted, MR-Egger, weighted median, simple mode, and weighted mode to evaluate the causal effect of rheumatoid arthritis on clonal hematopoiesis. The two-sample MR analysis suggested a strong causal relationship between rheumatoid arthritis and clonal hematopoiesis by inverse-variance weighted (OR = 1.002311673, 95% CI [1.000110757, 1.004517433], p = .039706) and weighted median (OR = 1.002311673, 95% CI [1.000110757, 1.004517433], p = .039518447) methods. No significant pleiotropy or heterogeneity was found in the sensitivity analysis. These results supported a potentially causal relationship between rheumatoid arthritis and clonal hematopoiesis, and the exposure of rheumatoid arthritis increased the risks of clonal hematopoiesis. Our findings highlight the importance of how chronic inflammation and immune activation induced rheumatoid arthritis enhances the risks of clonal hematopoiesis, and that early intervention with rheumatoid arthritis patients might reduce the clonal hematopoiesis risks in rheumatoid arthritis patients. Moreover, our study provides clues for prediction of risk factors and potential mechanisms of clonal hematopoiesis.

An overview of circumstances in which twins take the place of their co-twin is presented. Various explanations and speculations are proposed for understanding twins' willingness to do so in certain situations. This section is followed by reviews of timely twin research, namely single versus multiple embryo transfer; neurimaging of twins with periventricular nodular heterotopia; a twin dietary comparison; and a new book of twin-related readings from Hungary. The final portion of this article concerns human interest stories that both inform and entertain. They involve valedictorian and salutatorian twins; a mother delivering twins at age seventy; twins reunited by TikTok; a new film about twins with selective mutism; and twins becoming doctors.