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European Journal of Orthodontics Nov 2023The objective of this study was to examine the relative contributions of genetic and environmental influences on variation in dental arch form in individuals who have...
OBJECTIVE
The objective of this study was to examine the relative contributions of genetic and environmental influences on variation in dental arch form in individuals who have largely completed their craniofacial growth.
MATERIAL AND METHODS
The subjects of this study comprised dental casts of 50 monozygotic twins and 24 dizygotic twins from the collection of records of twins housed at the Adelaide Dental School, Australia. The subjects were of Western European descent, with an average age of 20.93 ± 5.58 years. Dental casts were scanned using a 3D scanner to analyse the dental arch form. Landmark-based inter-arch and intra-arch measurements were performed. Structural equation modelling was employed to analyse the quantitative data using the normal assumptions of the twin model.
RESULTS
Genetic modelling revealed that additive genetic and unique environmental factors best explained the observed variation for all occlusal traits measured, except for mandibular intercanine width. High heritability was observed for most intra-arch occlusal variables (0.61-0.85) including the maxillary and mandibular intercanine and intermolar widths, arch depth and perimeter. In contrast, moderate heritability was found for inter-arch occlusal variables (0.52-0.59) such as overjet and overbite. Sexual dimorphism was evident, with males displaying larger posterior arch width than females (P < 0.05).
LIMITATIONS
Our sample was limited to individuals of Western European ancestry.
CONCLUSION
The predominant source of occlusal variation within this group of Australian twins of Western European descent was controlled by genetic effects, and most were highly heritable. Generally, intra-arch occlusal variables showed greater heritability compared with inter-arch occlusal variables.
Topics: Male; Female; Humans; Adolescent; Young Adult; Adult; Dental Arch; Australia; Malocclusion, Angle Class II; Overbite; Twins, Monozygotic
PubMed: 37861389
DOI: 10.1093/ejo/cjad054 -
Frontiers in Psychology 2023Much of our understanding of infant psychological development relies on an in-person, laboratory-based assessment. This limits research generalizability, scalability,...
INTRODUCTION
Much of our understanding of infant psychological development relies on an in-person, laboratory-based assessment. This limits research generalizability, scalability, and equity in access. One solution is the development of new, remotely deployed assessment tools that do not require real-time experimenter supervision.
METHODS
The current nationwide (Sweden) infant twin study assessed participants remotely via their caregiver's tablets ( = 104, ages 3 to 17 months). To anchor our findings in previous research, we used a gaze-following task where experimental and age effects are well established.
RESULTS
Closely mimicking results from conventional eye tracking, we found that a full head movement elicited more gaze following than isolated eye movements. Furthermore, predictably, we found that older infants followed gaze more frequently than younger infants. Finally, while we found no indication of genetic contributions to gaze-following accuracy, the latency to disengage from the gaze cue and orient toward a target was significantly more similar in monozygotic twins than in dizygotic twins, an indicative of heritability.
DISCUSSION
Together, these results highlight the potential of remote assessment of infants' psychological development, which can improve generalizability, inclusion, and scalability in developmental research.
PubMed: 37854132
DOI: 10.3389/fpsyg.2023.1223267 -
Scientific Reports Oct 2023Considerable evidence supports the role of present-moment attention, a central feature of mindfulness, in subjective wellbeing maintenance and enhancement. Yet it is not...
Considerable evidence supports the role of present-moment attention, a central feature of mindfulness, in subjective wellbeing maintenance and enhancement. Yet it is not clear why such a relation exists. This study examined the genetic and environmental contributions of present-moment attention to subjective wellbeing. Consistent with the "generalist genes hypothesis" and prior evidence, we hypothesized that presence and subjective wellbeing would show a substantial genetic correlation and smaller environmental correlation. Using a large epidemiological sample of healthy 16-year-old twins in the United Kingdom (N = 1136 monozygotic (MZ) and dizygotic (DZ) twin pairs), genetic overlap was found between presence and the cognitive component of subjective wellbeing (life satisfaction), and to a lesser extent, the affective component of subjective wellbeing (operationalized as happiness). The non-shared environmental overlap between these constructs was substantial. This study provides the first evidence known to us showing that present-centered attention, a primary component of mindfulness, has both genetic and environmental overlap with subjective wellbeing. The findings have implications for understanding mechanisms by which presence is associated with positive emotions and life satisfaction, and suggest, pending additional research, that mindfulness-based interventions to enhance wellbeing may be best suited to those with a genetic propensity toward mindful presence.
Topics: Humans; Adolescent; Twins, Dizygotic; Happiness; Mindfulness; United Kingdom; Twins, Monozygotic
PubMed: 37838734
DOI: 10.1038/s41598-023-42810-x -
BMC Oral Health Oct 2023The aims of this study were to investigate and compare the prevalence of dental caries and the frequency of oral habits, molar relationships and occlusal traits between...
OBJECTIVE
The aims of this study were to investigate and compare the prevalence of dental caries and the frequency of oral habits, molar relationships and occlusal traits between children of multiple births, and singletons, and to determine the relative contributions of genetics and environmental factors to these parameters by using twin study design.
METHODS
The study group consisted of 345 multiple births (34 monozygotic and 122 dizygotic twin pairs, 11 sets of triplets) and 345 singletons between the ages of 2 and 17. The prevalence of dental caries, and the frequency of tooth brushing, the children's oral habits, molar relationships, and occlusal traits were recorded.
RESULTS
The percentage of children who brushed their teeth more than twice daily was statistically significantly higher in multiple births than in singletons. Higher correlation coefficients were found in dental caries index, except for decayed, filled (df) (2-5 age group) and filled (f) (6-11 age group), in the monozygotic twin pairs compared to those in the dizygotic twin pairs. In children between the ages of 6 and 11 years, mouth breathing, bruxism, lip biting, and pencil biting were higher in singletons than in children of multiple births. There were statistically significant differences between children of multiple births and singletons, with increased overjet in the 2-5 year age group being observed.
CONCLUSION
When analyzing these parameters, environmental factors must also be investigated. Due to the low incidence of twin births, longitudinal follow-up studies with more twin pairs are necessary to determine whether these results are generalizable.
Topics: Adolescent; Child; Child, Preschool; Humans; Bruxism; Dental Caries; Tooth; Twins, Dizygotic; Twins, Monozygotic
PubMed: 37814291
DOI: 10.1186/s12903-023-03426-9 -
Journal of Dental Sciences Oct 2023Twin studies are crucial to assess the relative contribution of genetic and environmental factors. This study was conducted to evaluate association between deleterious...
ABSTRACT BACKGROUND/PURPOSE
Twin studies are crucial to assess the relative contribution of genetic and environmental factors. This study was conducted to evaluate association between deleterious oral habits and dental caries-periodontal parameters among Turkish twins.
MATERIALS AND METHODS
The study comprised 143 pairs of dizygotic (DZ) twins and 59 pairs of monozygotic (MZ) twins aged 3-15 years. Twins were examined for dental caries, plaque index, gingival index, bleeding on probing and deleterious oral habits. Mann Whitney U test was used to examine the data.
RESULTS
The MZ twin pairs consisted of 60 male and 58 female twin pairs, whereas the DZ twin pairs consisted of 144 male and 142 female. The mean age of the twins was 9.63 ± 3.0 in MZ twins and 9.47 ± 3.2 in DZ twins. The mean DMFS value of MZ twins with bruxism is higher than those of MZ twins without bruxism ( = 0.001). The mean DMFS value of DZ twins with pacifier sucking is lower than those without ( = 0.007). A statistically significant difference was found between MZ twins with and without nail biting in terms of bleeding on probing and dmfs values ( = 0.035; = 0.012). The mean values of the plaque index increased due to the mouth breathing in DZ twins ( = 0.024). Regarding the bleeding on probing, there was a statistically significant difference between MZ twins with and without atypical swallowing ( = 0.016).
CONCLUSION
These findings suggest that dental caries-periodontal parameters are similarly affected by deleterious oral habits in MZ and DZ twins.
PubMed: 37799885
DOI: 10.1016/j.jds.2023.05.009 -
Materia Socio-medica Sep 2023Twin pregnancies make up 2% to 4% of all births. Incidence of spontaneous twin pregnancies varies around the world, with percentages ranging from 8/1000 to >17/1000...
BACKGROUND
Twin pregnancies make up 2% to 4% of all births. Incidence of spontaneous twin pregnancies varies around the world, with percentages ranging from 8/1000 to >17/1000 births. The variation in twin pregnancy rates is thought to be due to dizygotic pregnancies, since monozygotic pregnancies have a consistent incidence of 3.5/1000 to 4/1000 births. The incidence of twin pregnancies after the widespread use of assisted reproduction has increased significantly.
OBJECTIVE
The purpose of the present study is to investigate factors , who contribute to improve the perinatal outcome in twin pregnancies. Support will be provided by the results of twin pregnancies by the Department of Obstetrics and Gynaecology of Demokrition University of Thrace (Alexandroupolis, Greece) in the last fifteen years.
METHODS
From the above Department, data were collected on the number of twin pregnancies, maternal age, gestational age, mode of delivery (spontaneous delivery or caesarean section), birth weight and rate of twin pregnancies with assisted reproduction.
RESULTS
The results showed the increasing trend of twin pregnancies and births. A total of 304 twin pregnancies were identified (rate 2.75%). The rate of assisted reproduction was 34.83% in our sample, while the rate of cesarean deliveries was 95.5%, showing a large increase in recent years. In ten cases, normal delivery was successfully performed. The gestational age in twin pregnancies that ended with normal delivery was 37.37 + 3 weeks and the fetuses were both cephalic presentations. The main reason for admission of newborns to the NICU Department was prematurity.
CONCLUSION
The constantly improving education of perinatalists and understanding of the pathophysiology may lead to individualization of their treatment, and improvement of their prognosis based on recent scientific data from other international centers.
PubMed: 37795161
DOI: 10.5455/msm.2023.35.215-221 -
European Review For Medical and... Sep 2023Autoimmune diseases (ADs) are common conditions in which an individual's immune system reacts against its healthy cells. This condition is a common cause of morbidity... (Review)
Review
Autoimmune diseases (ADs) are common conditions in which an individual's immune system reacts against its healthy cells. This condition is a common cause of morbidity and mortality, with an estimated prevalence ranging from 5 per 100,000 to more than 500 per 100,000. According to the National Stem Cell Foundation (NSCF), ADs are prevalent in about 4% of the world's population, which creates a burden on society due to the high treatment cost. ADs show a clear gender bias with a higher prevalence among women, occurring at a rate of 2:1 female-to-male ratio. The etiology of ADs includes genetic and environmental factors. ADs are more likely to develop in genetically susceptible individuals. The higher concordance ratio between monozygotic twins compared to dizygotic twins or other siblings validates the role of genetic factors in the pathogenesis of many ADs. ADs diagnosis includes conventional immunoassay such as indirect immunofluorescence, complement fixation, passive agglutination, autoantibodies detection, and most recent advances, including multiplex platforms such as microspots, line-blot, addressable microbeads and barcoded nanoparticles that allow multiplex parallel testing of autoantibodies. ADs treatment includes biological and synthetic drugs that block many pathways and components of the immune system, including Janus kinase (JAK) inhibitors, non-receptor tyrosine-protein kinase (TYK2), and other cytokines. Generally, recent immune-modulatory drugs used in ADs treatment are non-disease specific with broad action and are associated with many side effects like infection and malignant diseases. Furthermore, gene therapy seeks to control the levels of proinflammatory cytokine molecules and lymphocyte infiltration through the delivery and expression of therapeutic genes. Recent genomic-wide association studies (GWAS) have allowed the identification of various genetic loci associated with disease susceptibility and have revealed candidate genes that can be used in targeted therapeutics. This review summarizes recent literature on the genetic factors associated with susceptibility to the 11 most common ADs, namely: Type 1 diabetes mellitus (T1DM), Multiple sclerosis (MS), Grave's disease, Sjögren's syndrome (SS), Celiac disease, Hashimoto's thyroiditis (HT), Anti-phospholipid syndrome (APS), Autoimmune hemolytic anemia, Rheumatoid arthritis (RA), Systemic lupus erythematosus (SLE), and Scleroderma (systemic sclerosis).
Topics: Female; Male; Humans; Genome-Wide Association Study; Sexism; Autoimmune Diseases; Sjogren's Syndrome; Lupus Erythematosus, Systemic; Autoantibodies; Scleroderma, Systemic
PubMed: 37782163
DOI: 10.26355/eurrev_202309_33772 -
Genes Sep 2023Esophageal atresia (EA) is the most common malformation of the upper gastrointestinal tract. The estimated incidence of EA is 1 in 3500 births. EA is more frequently...
Esophageal atresia (EA) is the most common malformation of the upper gastrointestinal tract. The estimated incidence of EA is 1 in 3500 births. EA is more frequently observed in boys and in twins. The exact cause of isolated EA remains unknown; a multifactorial etiology, including epigenetic gene expression modifications, is considered. The study included six pairs of twins (three pairs of monozygotic twins and three pairs of dizygotic twins) in which one child was born with EA as an isolated defect, while the other twin was healthy. DNA samples were obtained from the blood and esophageal tissue of the child with EA as well as from the blood of the healthy twin. The reduced representation bisulfite sequencing (RRBS) technique was employed for a whole-genome methylation analysis. The analyses focused on comparing the CpG island methylation profiles between patients with EA and their healthy siblings. Hypermethylation in the promoters of 219 genes and hypomethylation in the promoters of 78 genes were observed. A pathway enrichment analysis revealed the statistically significant differences in methylation profile of 10 hypermethylated genes in the Rho GTPase pathway, previously undescribed in the field of EA (, and ).
Topics: Male; Child; Humans; Esophageal Atresia; Twins, Monozygotic; Twins, Dizygotic; CpG Islands; Epigenesis, Genetic; Proto-Oncogene Proteins; Guanine Nucleotide Exchange Factors; Rho Guanine Nucleotide Exchange Factors
PubMed: 37761962
DOI: 10.3390/genes14091822 -
Scientific Reports Sep 2023Type 1 diabetes (T1D) is characterized by the progressive destruction of pancreatic β-cells, leading to insulin deficiency and lifelong dependency on exogenous insulin....
Type 1 diabetes (T1D) is characterized by the progressive destruction of pancreatic β-cells, leading to insulin deficiency and lifelong dependency on exogenous insulin. Higher estimates of heritability rates in monozygotic twins, followed by dizygotic twins and sib-pairs, indicate the role of genetics in the pathogenesis of T1D. The incidence and prevalence of T1D are alarmingly high in Kuwait. Consanguineous marriages account for 50-70% of all marriages in Kuwait, leading to an excessive burden of recessive allele enrichment and clustering of familial disorders. Thus, genetic studies from this Arab region are expected to lead to the identification of novel gene loci for T1D. In this study, we performed linkage analyses to identify the recurrent genetic variants segregating in high-risk Kuwaiti families with T1D. We studied 18 unrelated Kuwaiti native T1D families using whole exome sequencing data from 86 individuals, of whom 37 were diagnosed with T1D. The study identified three potential loci with a LOD score of ≥ 3, spanning across four candidate genes, namely SLC17A1 (rs1165196:pT269I), SLC17A3 (rs942379: p.S370S), TATDN2 (rs394558:p.V256I), and TMEM131L (rs6848033:p.R190R). Upon examination of missense variants from these genes in the familial T1D dataset, we observed a significantly increased enrichment of the genotype homozygous for the minor allele at SLC17A3 rs56027330_p.G279R accounting for 16.2% in affected children from 6 unrelated Kuwaiti T1D families compared to 1000 genomes Phase 3 data (0.9%). Data from the NephQTL database revealed that the rs1165196, rs942379, rs394558, and rs56027330 SNPs exhibited genotype-based differential expression in either glomerular or tubular tissues. Data from the GTEx database revealed rs942379 and rs394558 as QTL variants altering the expression of TRIM38 and IRAK2 respectively. Global genome-wide association studies indicated that SLC17A1 rs1165196 and other variants from SLC17A3 are associated with uric acid concentrations and gout. Further evidence from the T1D Knowledge portal supported the role of shortlisted variants in T1D pathogenesis and urate metabolism. Our study suggests the involvement of SLC17A1, SLC17A3, TATDN2, and TMEM131L genes in familial T1D in Kuwait. An enrichment selection of genotype homozygous for the minor allele is observed at SLC17A3 rs56027330_p.G279R variant in affected members of Kuwaiti T1D families. Future studies may focus on replicating the findings in a larger T1D cohort and delineate the mechanistic details of the impact of these novel candidate genes on the pathophysiology of T1D.
Topics: Child; Humans; Diabetes Mellitus, Type 1; Kuwait; Exome Sequencing; Genome-Wide Association Study; Insulin; Sodium-Phosphate Cotransporter Proteins, Type I
PubMed: 37696853
DOI: 10.1038/s41598-023-42255-2 -
IScience Sep 2023Functional connectomes (FCs) containing pairwise estimations of functional couplings between pairs of brain regions are commonly represented by correlation matrices. As...
Functional connectomes (FCs) containing pairwise estimations of functional couplings between pairs of brain regions are commonly represented by correlation matrices. As symmetric positive definite matrices, FCs can be transformed via tangent space projections, resulting into tangent-FCs. Tangent-FCs have led to more accurate models predicting brain conditions or aging. Motivated by the fact that tangent-FCs seem to be better biomarkers than FCs, we hypothesized that tangent-FCs have also a higher fingerprint. We explored the effects of six factors: fMRI condition, scan length, parcellation granularity, reference matrix, main-diagonal regularization, and distance metric. Our results showed that identification rates are systematically higher when using tangent-FCs across the "fingerprint gradient" (here including test-retest, monozygotic and dizygotic twins). Highest identification rates were achieved when minimally (0.01) regularizing FCs while performing tangent space projection using Riemann reference matrix and using correlation distance to compare the resulting tangent-FCs. Such configuration was validated in a second dataset (resting-state).
PubMed: 37694156
DOI: 10.1016/j.isci.2023.107624