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Genes Oct 2023The goal of the study was to explore the spectrum of pathogenic variants in the RPGR gene in a group of male Polish patients with a retinitis pigmentosa (RP) phenotype....
The goal of the study was to explore the spectrum of pathogenic variants in the RPGR gene in a group of male Polish patients with a retinitis pigmentosa (RP) phenotype. A total of 45 male index patients, including twins, being members of 44 families, were screened for pathogenic variants in the RPGR gene via the direct sequencing of PCR-amplified genomic DNA and underwent a comprehensive ophthalmological examination in one center located in Poland. A total of two pathogenic and five likely pathogenic variants in eight patients (18%) were detected in the studied cohort. Of these, five variants were novel, and five disease-causing variants (71%) were identified within the ORF15 mutational hotspot of the RPGR gene. The median age of onset of the disease was 10 years (range 6-14 years), the median age during the examination was 30 years (range 20-47 years), and the median visual acuity was 0.4 (range 0.01-0.7). The majority of patients had middle constriction of the visual field and thinning of the central foveal thickness. Dizygotic twins bearing the same hemizygous mutation showed a different retinal phenotype in regard to the severity of the symptoms. This is the first RPGR mutation screening in Poland showing a prevalence of 18% of RPGR pathogenic mutations and likely pathogenic variants in the studied cohort of male patients with an RP phenotype.
Topics: Humans; Male; Child; Adolescent; Young Adult; Adult; Middle Aged; Poland; Eye Proteins; Pedigree; Phenotype; Retinitis Pigmentosa
PubMed: 37895299
DOI: 10.3390/genes14101950 -
The Journals of Gerontology. Series B,... Jan 2024The educational gradient in late-life health is well established. Despite this, there are still ambiguities concerning the role of underlying confounding by genetic...
OBJECTIVES
The educational gradient in late-life health is well established. Despite this, there are still ambiguities concerning the role of underlying confounding by genetic influences and gene-environment (GE) interplay. Here, we investigate the role of educational factors (attained and genetic propensities) on health and mortality in late life using genetic propensity for educational attainment (as measured by a genome-wide polygenic score, PGSEdu) and attained education.
METHODS
By utilizing genetically informative twin data from the Swedish Twin Registry (n = 14,570), we investigated influences of the educational measures, familial confounding as well as the possible presence of passive GE correlation on both objective and subjective indicators of late-life health, that is, the Frailty Index, Multimorbidity, Self-rated health, cardiovascular disease, and all-cause mortality.
RESULTS
Using between-within models to adjust for shared familial factors, we found that the relationship between educational level and health and mortality later in life persisted despite controlling for familial confounding. PGSEdu and attained education both uniquely predicted late-life health and mortality, even when mutually adjusted. Between-within models of PGSEdu on the health outcomes in dizygotic twins showed weak evidence for passive GE correlation (prGE) in the education-health relationship.
DISCUSSION
Both genetic propensity to education and attained education are (partly) independently associated with health in late life. These results lend further support for a causal education-health relationship but also raise the importance of genetic contributions and GE interplay.
Topics: Humans; Academic Success; Cardiovascular Diseases; Educational Status; Twins, Dizygotic
PubMed: 37862467
DOI: 10.1093/geronb/gbad153 -
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 -
American Journal of Medical Genetics.... Feb 2024We report a novel homozygous 49.6 kb deletion of chromosome 18q12.1 involving the last exon of DSG3 in dizygotic twins with phenotype consistent with acantholytic...
We report a novel homozygous 49.6 kb deletion of chromosome 18q12.1 involving the last exon of DSG3 in dizygotic twins with phenotype consistent with acantholytic blistering of the oral and laryngeal mucosa (ABOLM). The twin siblings presented predominantly with friability of the laryngeal and respiratory mucosa. This is only the second report in the literature of this unusual autosomal recessive blistering disorder. The diagnosis explains the mucosal phenotype of a pemphigus-like disorder without evidence of autoimmune dysfunction. The exclusion of an autoimmune basis has management implications. The deletion also involved the DSG2 gene, which is associated with arrhythmogenic right ventricular dysplasia (ARVD). The affected siblings and heterozygous parents do not show any cardiac phenotype at this time. Functional studies would further clarify how deletions resulting in loss of function of DSG3 may cause the reported phenotypes of DSG3-related ABOLM.
Topics: Humans; Laryngeal Mucosa; Homozygote; Desmoglein 3; Sequence Deletion; Exons
PubMed: 37850634
DOI: 10.1002/ajmg.a.63447 -
Ultrasound in Obstetrics & Gynecology :... Feb 2024To derive reference distributions of estimated fetal weight (EFW) in twins relative to singletons.
OBJECTIVE
To derive reference distributions of estimated fetal weight (EFW) in twins relative to singletons.
METHODS
Gestational-age- and chorionicity-specific reference distributions for singleton percentiles and EFW were fitted to data on 4391 twin pregnancies with two liveborn fetuses from four European centers, including 3323 dichorionic (DC) and 1068 monochorionic diamniotic (MCDA) twin pregnancies. Gestational age was derived using the larger of the two crown-rump length measurements obtained during the first trimester of pregnancy. EFW was obtained from ultrasound measurements of head circumference, abdominal circumference and femur length using the Hadlock formula. Singleton percentiles were obtained using the Fetal Medicine Foundation population weight charts for singleton pregnancies. Hierarchical models were fitted to singleton Z-scores with autoregressive terms for serial correlations within the same fetus and between twins from the same pregnancy. Separate models were fitted for DC and MCDA twins.
RESULTS
Fetuses from twin pregnancies tended to be smaller than singletons at the earliest gestational ages (16 weeks for MCDA and 20 weeks for DC twins). This was followed by a period of catch-up growth until around 24 weeks. After that, both DC and MCDA twins showed reduced growth. In DC twins, the EFW corresponding to the 50 percentile was at the 50 percentile of singleton pregnancies at 23 weeks, the 43 percentile at 28 weeks, the 32 percentile at 32 weeks and the 22 percentile at 36 weeks. In MCDA twins, the EFW corresponding to the 50 percentile was at the 36 percentile of singleton pregnancies at 24 weeks, the 29 percentile at 28 weeks, the 19 percentile at 32 weeks and the 12 percentile at 36 weeks.
CONCLUSIONS
In DC and, to a greater extent, MCDA twin pregnancies, fetal growth is reduced compared with that observed in singleton pregnancies. Furthermore, after 24 weeks, the divergence in growth trajectories between twin and singleton pregnancies becomes more pronounced as gestational age increases. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.
Topics: Pregnancy; Female; Humans; Perinatology; Fetal Development; Pregnancy, Twin; Gestational Age; Fetal Weight; Twins, Dizygotic; Retrospective Studies; Ultrasonography, Prenatal; Fetal Growth Retardation
PubMed: 37842873
DOI: 10.1002/uog.27514 -
Twin Research and Human Genetics : the... Oct 2023Astigmatism and myopia are two common ocular refractive errors that can impact daily life, including learning and productivity. Current knowledge suggests that the...
Astigmatism and myopia are two common ocular refractive errors that can impact daily life, including learning and productivity. Current knowledge suggests that the etiology of these conditions is the result of a complex interplay between genetic and environmental factors. Studies in populations of European ancestry have demonstrated a higher concordance of refractive errors in monozygotic (MZ) twins compared to dizygotic (DZ) twins. However, there is a lack of studies on genetically informative samples of multi-ethnic ancestry. This study aimed to estimate the genetic contribution to astigmatism and myopia in the Mexican population. A sample of 1399 families, including 243 twin pairs and 1156 single twins, completed a medical questionnaire about their own and their co-twin's diagnosis of astigmatism and myopia. Concordance rates for astigmatism and myopia were estimated, and heritability and genetic correlations were determined using a bivariate ACE Cholesky decomposition method, decomposed into A (additive genetic), C (shared environmental) and E (unique environmental) components. The results showed a higher concordance rate for astigmatism and myopia for MZ twins (.74 and .74, respectively) than for DZ twins (.50 and .55). The AE model, instead of the ACE model, best fitted the data. Based on this, heritability estimates were .81 for astigmatism and .81 for myopia, with a cross-trait genetic correlation of A = .80, nonshared environmental correlation E = .89, and a phenotypic correlation of P = .80. These results are consistent with previous findings in other populations, providing evidence for a similar genetic architecture of these conditions in the multi-ethnic Mexican population.
PubMed: 37842863
DOI: 10.1017/thg.2023.41 -
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