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Neuromuscular Disorders : NMD Jul 2024We report on genetic and environmental modulation of social cognition abilities and brain volume correlates in two monozygotic twins (Twin1 and Twin2) with genetically...
Different neuropsychological and brain volumetric profiles in a pair of identical twins with myotonic dystrophy type 1 indicate a non-genetic modulation of clinical phenotype.
We report on genetic and environmental modulation of social cognition abilities and brain volume correlates in two monozygotic twins (Twin1 and Twin2) with genetically confirmed myotonic dystrophy-type1 who grew up in different environmental settings. They both underwent neuropsychological assessment (i.e., Intelligent Quotient [IQ], theory of mind, emotion recognition tests), and MRI scanning to evaluate regional brain volumetrics compared to 10 gender and sex-matched healthy controls. Against a normal IQ level in both patients, Twin1 was more impaired in emotional processing and Twin2 in cognitive aspects of social cognition. Both patients showed grey matter (GM) atrophy in Brodmann Areas 23/31 (BA23/31) and BA7 bilaterally, while Twin2 showed additional GM loss in right BA46. Both patients showed a similar pattern of white matter atrophy involving the thalamus, basal ganglia, and uncinate fasciculus. White matter atrophy appeared to be mostly driven by genetics, while grey matter volumes appeared associated with different impairments in social cognition and possibly modulated by environment.
Topics: Humans; Myotonic Dystrophy; Twins, Monozygotic; Brain; Neuropsychological Tests; Male; Phenotype; Magnetic Resonance Imaging; Female; Adult; Atrophy; Gray Matter; Middle Aged; White Matter; Social Cognition
PubMed: 38810327
DOI: 10.1016/j.nmd.2024.04.007 -
Immunological Reviews May 2024Multiple sclerosis (MS) affects more than 2.8 million people worldwide but the distribution is not even. Although over 200 gene variants have been associated with... (Review)
Review
Multiple sclerosis (MS) affects more than 2.8 million people worldwide but the distribution is not even. Although over 200 gene variants have been associated with susceptibility, studies of genetically identical monozygotic twin pairs suggest that the genetic make-up is responsible for only about 20%-30% of the risk to develop disease, while the rest is contributed by milieu factors. Recently, a new, unexpected player has entered the ranks of MS-triggering or facilitating elements: the human gut microbiota. In this review, we summarize the present knowledge of microbial effects on formation of a pathogenic autoreactive immune response targeting the distant central nervous system and delineate the approaches, both in people with MS and in MS animal models, which have led to this concept. Finally, we propose that a tight combination of investigations of human patients with studies of suitable animal models is the best strategy to functionally characterize disease-associated microbiota and thereby contribute to deciphering pathogenesis of a complex human disease.
PubMed: 38809041
DOI: 10.1111/imr.13357 -
The Journal of Medicine and Philosophy May 2024It is often argued that certain metaphysical complications surrounding the phenomenon of monozygotic twinning force us to conclude that, prior to the point at which...
It is often argued that certain metaphysical complications surrounding the phenomenon of monozygotic twinning force us to conclude that, prior to the point at which twinning is no longer possible, the zygote or early embryo cannot be considered an individual human organism. In this essay, I argue, on the contrary, that there are in fact several ways of making sense of monozygotic twinning that uphold the humanity of the original zygote, but also that there is no easy answer to what happens when the human zygote twins. All of the options available carry with them one or more surprising, alarming, or otherwise counterintuitive implications. All things considered, I conclude that the "budding option," according to which the original human organism present before twinning carries on as one of the resulting embryos but not the other, is the most plausible explanation of what happens when a human zygote twins.
PubMed: 38805694
DOI: 10.1093/jmp/jhae022 -
Human Brain Mapping Jun 2024Twin studies have found gross cerebellar volume to be highly heritable. However, whether fine-grained regional volumes within the cerebellum are similarly heritable is...
Twin studies have found gross cerebellar volume to be highly heritable. However, whether fine-grained regional volumes within the cerebellum are similarly heritable is still being determined. Anatomical MRI scans from two independent datasets (QTIM: Queensland Twin IMaging, N = 798, mean age 22.1 years; QTAB: Queensland Twin Adolescent Brain, N = 396, mean age 11.3 years) were combined with an optimised and automated cerebellum parcellation algorithm to segment and measure 28 cerebellar regions. We show that the heritability of regional volumetric measures varies widely across the cerebellum ( 47%-91%). Additionally, the good to excellent test-retest reliability for a subsample of QTIM participants suggests that non-genetic variance in cerebellar volumes is due primarily to unique environmental influences rather than measurement error. We also show a consistent pattern of strong associations between the volumes of homologous left and right hemisphere regions. Associations were predominantly driven by genetic effects shared between lobules, with only sparse contributions from environmental effects. These findings are consistent with similar studies of the cerebrum and provide a first approximation of the upper bound of heritability detectable by genome-wide association studies.
Topics: Humans; Cerebellum; Male; Adolescent; Female; Magnetic Resonance Imaging; Young Adult; Child; Adult; Organ Size; Twins, Monozygotic
PubMed: 38798116
DOI: 10.1002/hbm.26717 -
Journal of Clinical Immunology May 2024
Correction to: Monozygotic Twins with MAGT1 Deficiency and Epstein-Barr virus-positive Classic Hodgkin Lymphoma Receiving anti-CD30 CAR T-cell Immunotherapy: A case Report.
PubMed: 38795171
DOI: 10.1007/s10875-024-01723-8 -
Genes May 2024Schizophrenia symptomatology includes negative symptoms and cognitive impairment. Several studies have linked schizophrenia with the PDE4 family of enzymes due to their... (Meta-Analysis)
Meta-Analysis
Schizophrenia symptomatology includes negative symptoms and cognitive impairment. Several studies have linked schizophrenia with the PDE4 family of enzymes due to their genetic association and function in cognitive processes such as long-term potentiation. We conducted a systematic gene expression meta-analysis of four PDE4 genes (PDE4A-D) in 10 brain sample datasets (437 samples) and three blood sample datasets (300 samples). Subsequently, we measured mRNA levels in iPSC-derived hippocampal dentate gyrus neurons generated from fibroblasts of three groups: healthy controls, healthy monozygotic twins (MZ), and their MZ siblings with schizophrenia. We found downregulation of PDE4B in brain tissues, further validated by independent data of the CommonMind consortium (515 samples). Interestingly, the downregulation signal was present in a subgroup of the patients, while the others showed no differential expression or even upregulation. Notably, PDE4A, PDE4B, and PDE4D exhibited upregulation in iPSC-derived neurons compared to healthy controls, whereas in blood samples, PDE4B was found to be upregulated while PDE4A was downregulated. While the precise mechanism and direction of altered PDE4 expression necessitate further investigation, the observed multilevel differential expression across the brain, blood, and iPSC-derived neurons compellingly suggests the involvement of PDE4 genes in the pathophysiology of schizophrenia.
Topics: Schizophrenia; Humans; Cyclic Nucleotide Phosphodiesterases, Type 4; Induced Pluripotent Stem Cells; Neurons; Brain; Male; Female; Adult
PubMed: 38790238
DOI: 10.3390/genes15050609 -
Early Human Development Jul 2024Necrotizing enterocolitis (NEC) is a major cause of neonatal morbidity and mortality in preterm neonates, yet its pathophysiology remains unclear. The aim of this study...
Necrotizing enterocolitis (NEC) is a major cause of neonatal morbidity and mortality in preterm neonates, yet its pathophysiology remains unclear. The aim of this study is to evaluate risk factors for NEC using an identical twin model. In this case-control study, all monochorionic twin pairs born in our center in 2002-2020 were retrospectively reviewed for NEC. Potential risk factors for NEC were studied. For within-pair comparison, outcomes were compared between affected and unaffected twins. Within-pair analyses showed that the twin with NEC had a lower birth weight compared to its unaffected co-twin (1100 (913-1364) vs. 1339 (1093-1755) grams). Median gestational age at birth and birth weight were lower in twin pairs in the NEC-group compared to the no-NEC group, 29.1 weeks (27.8-30.8) versus 33.6 (30.7-36.0) and 1221 g (1010-1488) versus 1865 (1356-2355) respectively. Twin pregnancies in the NEC-group were more often complicated by twin-to-twin transfusion syndrome compared to the no-NEC-group (70 % (14/20) vs. 49 % (472/962)), particularly when treated with amnioreduction. This unique population of identical twins confirms that preterm neonates with a relatively lower birth weight are more prone to develop NEC compared to their co-twin, regardless of other genetic, maternal and obstetrical factors.
Topics: Humans; Enterocolitis, Necrotizing; Infant, Newborn; Female; Twins, Monozygotic; Male; Infant, Premature; Pregnancy; Case-Control Studies; Diseases in Twins; Risk Factors; Retrospective Studies; Birth Weight; Gestational Age
PubMed: 38781714
DOI: 10.1016/j.earlhumdev.2024.106052 -
BMC Medical Genomics May 2024Thoracic aortic aneurysm/dissection (TAAD) and patent ductus arteriosus (PDA) are serious autosomal-dominant diseases affecting the cardiovascular system. They are...
BACKGROUND
Thoracic aortic aneurysm/dissection (TAAD) and patent ductus arteriosus (PDA) are serious autosomal-dominant diseases affecting the cardiovascular system. They are mainly caused by variants in the MYH11 gene, which encodes the heavy chain of myosin 11. The aim of this study was to evaluate the genotype-phenotype correlation of MYH11 from a distinctive perspective based on a pair of monozygotic twins.
METHODS
The detailed phenotypic characteristics of the monozygotic twins from the early fetal stage to the infancy stage were traced and compared with each other and with those of previously documented cases. Whole-exome and Sanger sequencing techniques were used to identify and validate the candidate variants, facilitating the analysis of the genotype-phenotype correlation of MYH11.
RESULTS
The monozygotic twins were premature and presented with PDA, pulmonary hypoplasia, and pulmonary hypertension. The proband developed heart and brain abnormalities during the fetal stage and died at 18 days after birth, whereas his sibling was discharged after being cured and developed normally post follow-up. A novel variant c.766 A > G p. (Ile256Val) in MYH11 (NM_002474.2) was identified in the monozygotic twins and classified as a likely pathogenic variant according to the American College of Medical Genetics/Association for Molecular Pathology guidelines. Reviewing the reported cases (n = 102) showed that the penetrance of MYH11 was 82.35%, and the most common feature was TAAD (41.18%), followed by PDA (22.55%), compound TAAD and PDA (9.80%), and other vascular abnormalities (8.82%). The constituent ratios of null variants among the cases with TAAD (8.60%), PDA (43.8%), or compound TAAD and PDA (28.6%) were significantly different (P = 0.01). Further pairwise comparison of the ratios among these groups showed that there were significant differences between the TAAD and PDA groups (P = 0.006).
CONCLUSION
This study expands the mutational spectrum of MYH11 and provides new insights into the genotype-phenotype correlation of MYH11 based on the monozygotic twins with variable clinical features and outcomes, indicating that cryptic modifiers and complex mechanisms beside the genetic variants may be involved in the condition.
Topics: Humans; Twins, Monozygotic; Myosin Heavy Chains; Male; Genetic Association Studies; Infant, Newborn; Phenotype; Cardiac Myosins; Aortic Aneurysm, Thoracic; Ductus Arteriosus, Patent; Female; Mutation; Aortic Dissection
PubMed: 38773466
DOI: 10.1186/s12920-024-01908-5 -
International Journal of Obesity (2005) May 2024Central obesity poses significant health risks because it increases susceptibility to multiple chronic diseases. Epigenetic features such as DNA methylation may be...
OBJECTIVES
Central obesity poses significant health risks because it increases susceptibility to multiple chronic diseases. Epigenetic features such as DNA methylation may be associated with specific obesity traits, which could help us understand how genetic and environmental factors interact to influence the development of obesity. This study aims to identify DNA methylation sites associated with the waist circumference (WC) in Northern Han Chinese population, and to elucidate potential causal relationships.
METHODS
A total of 59 pairs of WC discordant monozygotic twins (ΔWC >0) were selected from the Qingdao Twin Registry in China. Generalized estimated equation model was employed to estimate the methylation levels of CpG sites on WC. Causal relationships between methylation and WC were assessed through the examination of family confounding factors using FAmiliaL CONfounding (ICE FALCON). Additionally, the findings of the epigenome-wide analysis were corroborated in the validation stage.
RESULTS
We identified 26 CpG sites with differential methylation reached false discovery rate (FDR) < 0.05 and 22 differentially methylated regions (slk-corrected p < 0.05) strongly linked to WC. These findings provided annotations for 26 genes, with notable emphasis on MMP17, ITGA11, COL23A1, TFPI, A2ML1-AS1, MRGPRE, C2orf82, and NINJ2. ICE FALCON analysis indicated the DNA methylation of ITGA11 and TFPI had a causal effect on WC and vice versa (p < 0.05). Subsequent validation analysis successfully replicated 10 (p < 0.05) out of the 26 identified sites.
CONCLUSIONS
Our research has ascertained an association between specific epigenetic variations and WC in the Northern Han Chinese population. These DNA methylation features can offer fresh insights into the epigenetic regulation of obesity and WC as well as hints to plausible biological mechanisms.
PubMed: 38773251
DOI: 10.1038/s41366-024-01538-y -
Medicine and Science in Sports and... May 2024We investigated whether longitudinally assessed physical activity (PA) and adherence specifically to World Health Organization PA guidelines mitigates or moderates...
PURPOSE
We investigated whether longitudinally assessed physical activity (PA) and adherence specifically to World Health Organization PA guidelines mitigates or moderates mortality risk regardless of genetic liability to cardiovascular disease (CVD). We also estimated the causality of the PA-mortality association.
METHODS
The study used the older Finnish Twin Cohort (FTC) with 4,897 participants aged 33-60 years (54.3% women). Genetic liability to coronary heart disease, systolic and diastolic blood pressure was estimated with polygenic risk scores (PRSs) derived from the Pan-UK Biobank (N ≈ 400,000; > 1,000,000 genetic variants). Leisure-time PA was assessed with validated and structured questionnaires three times during 1975-1990. The main effects of adherence to PA guidelines and the PRS × PA interactions were evaluated with Cox proportional hazards models against all-cause and CVD mortality. A co-twin control design with 180 monozygotic twin pairs discordant for meeting the guidelines was used for causal inference.
RESULTS
During the 17.4-year (mean) follow-up (85,136 person-years), 1,195 participants died, with 389 CVD deaths. One standard deviation higher PRSs were associated with a 17%-24% higher CVD mortality risk but not with all-cause mortality except for the PRS for diastolic blood pressure. Adherence to PA guidelines did not show significant independent main effects or interactions with all-cause or CVD mortality. Twins whose activity levels adhered to PA guidelines over a 15-year period did not have statistically significantly reduced mortality risk compared to their less active identical twin sibling. The findings were similar among high, intermediate, and low genetic risk levels for CVD.
CONCLUSIONS
The genetically informed FTC data could not confirm that adherence to PA guidelines either mitigates or moderates genetic CVD risk or causally reduces mortality risk.
PubMed: 38768019
DOI: 10.1249/MSS.0000000000003482