scholarly journals A prospective study of time-dependent exposures to childhood adversity and DNA methylation in childhood and adolescence

Author(s):  
Alexandre A Lussier ◽  
Yiwen Zhu ◽  
Brooke J Smith ◽  
Janine Cerutti ◽  
Andrew Simpkin ◽  
...  

Background: Childhood adversity influences long-term health, particularly if experienced during sensitive periods in development when physiological systems are more responsive to environmental influences. Although the underlying mechanisms remain unclear, prior studies suggest that DNA methylation (DNAm) may capture these time-dependent effects of childhood adversity. However, it remains unknown whether DNAm alterations persist into adolescence and how the timing of adversity might influence DNAm trajectories across development. Methods: We examined the relationship between time-dependent adversity and genome-wide DNAm measured at three waves from birth to adolescence using prospective data from the Avon Longitudinal Study of Parents and Children. We first assessed the relationship between the timing of exposure to seven types of adversity (measured 5-8 times between ages 0-11) and DNAm at age 15 using a structured life course modeling approach. We also characterized the persistence into adolescence of associations identified from age 7 DNAm, as well as the influence of adversity on DNAm trajectories from ages 0-15. Results: Adversity was associated with differences in age 15 DNAm at 24 loci (FDR<0.05). Most loci (19 of 24) were associated with adversity (i.e., physical/sexual abuse, one-adult households, caregiver abuse) that occurred between ages 3-5. Although no DNAm differences present at age 7 persisted into adolescence, we identified seven unique types of DNAm trajectories across development, which highlighted diverse effects of childhood adversity on DNAm. Conclusions: Our results suggest that childhood adversity, particularly between ages 3-5, can influence the trajectories of DNAm across development, exerting both immediate and latent effects on the epigenome.

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Doretta Caramaschi ◽  
Charlie Hatcher ◽  
Rosa H. Mulder ◽  
Janine F. Felix ◽  
Charlotte A. M. Cecil ◽  
...  

AbstractThe occurrence of seizures in childhood is often associated with neurodevelopmental impairments and school underachievement. Common genetic variants associated with epilepsy have been identified and epigenetic mechanisms have also been suggested to play a role. In this study, we analyzed the association of genome-wide blood DNA methylation with the occurrence of seizures in ~ 800 children from the Avon Longitudinal Study of Parents and Children, UK, at birth (cord blood), during childhood, and adolescence (peripheral blood). We also analyzed the association between the lifetime occurrence of any seizures before age 13 with blood DNA methylation levels. We sought replication of the findings in the Generation R Study and explored causality using Mendelian randomization, i.e., using genetic variants as proxies. The results showed five CpG sites which were associated cross-sectionally with seizures either in childhood or adolescence (1–5% absolute methylation difference at pFDR < 0.05), although the evidence of replication in an independent study was weak. One of these sites was located in the BDNF gene, which is highly expressed in the brain, and showed high correspondence with brain methylation levels. The Mendelian randomization analyses suggested that seizures might be causal for changes in methylation rather than vice-versa. In conclusion, we show a suggestive link between seizures and blood DNA methylation while at the same time exploring the limitations of conducting such study.


2019 ◽  
Author(s):  
Doretta Caramaschi ◽  
Charlie Hatcher ◽  
Rosa H. Mulder ◽  
Janine F. Felix ◽  
Charlotte A. M. Cecil ◽  
...  

ABSTRACTThe occurrence of seizures in childhood is often associated with neurodevelopmental impairments and school underachievement. Common genetic variants associated with epilepsy have been identified and epigenetic mechanisms have also been suggested to play a role. In this study we analysed the association of genome-wide blood DNA methylation with the occurrence of seizures in ∼800 children from the Avon Longitudinal Study of Parents and Children, UK, at birth (cord blood), during childhood and adolescence (peripheral blood). We also analysed the association between the lifetime occurrence of any seizures before age 13 with blood DNA methylation levels. We sought replication of the findings in the Generation R Study and explored causality using Mendelian randomization, i.e. using genetic variants as proxies. The results showed five CpG sites which were associated cross-sectionally with seizures either in childhood or adolescence (1-5% absolute methylation difference at pFDR<0.05), although the evidence of replication in an independent study was weak. One of these sites was located in the BDNF gene, which is highly expressed in the brain, and showed high correspondence with brain methylation levels. The Mendelian randomization analyses suggested that seizures might be causal for changes in methylation rather than vice-versa. In addition, seizure-associated methylation changes could affect other outcomes such as growth, cognitive skills and educational attainment. In conclusion, we present a link between seizures and DNA methylation which suggests that DNA methylation changes might mediate some of the effects of seizures on growth and neurodevelopment.


2021 ◽  
Author(s):  
Alexandre A. Lussier ◽  
Yiwen Zhu ◽  
Brooke J. Smith ◽  
Andrew J. Simpkin ◽  
Andrew D.A.C. Smith ◽  
...  

ABSTRACTIntroductionBiomedical research has grown increasingly cooperative, with several large consortia compiling and sharing epigenomic data. Since data are typically preprocessed by consortia prior to distribution, the implementation of new pipelines can lead to different versions of the same dataset. Analytic frameworks also constantly evolve to incorporate cutting-edge methods and shifting best practices. However, it remains unknown how differences in data and analytic versions alter the results of epigenome-wide analyses, which has broad implications for the replicability of epigenetic associations. Thus, we assessed the impact of these changes using a subsample of the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort.MethodsWe analyzed two versions of DNA methylation data, processed using separate preprocessing and analytic pipelines, to examine associations between childhood adversity and prenatal smoking exposure on DNA methylation at age 7. We performed two sets of analyses: (1) epigenome-wide association studies (EWAS); (2) Structured Life Course Modeling Approach (SLCMA), a two-stage method that models time-dependent effects. We also compared results from the SLCMA using more recent methodological recommendations.ResultsDifferences between ALSPAC data versions impacted both EWAS and SLCMA analyses, yielding different sets of associations at conventional p-value thresholds. However, the magnitude and direction of associations was generally consistent between data versions, regardless of significance thresholds. Updating the SLCMA analytic version similarly altered top associations, but time-dependent effects remained concordant.ConclusionsChanges to data and analytic versions influenced the results of epigenome-wide studies, particularly when using p-value thresholds as reference points for successful replication and stability.


2018 ◽  
Vol 69 (4) ◽  
pp. 354 ◽  
Author(s):  
Jialin Guo ◽  
Gaisheng Zhang ◽  
Huali Tang ◽  
Yulong Song ◽  
Shoucai Ma ◽  
...  

Variety DUOII is a multi-ovary line of common wheat (Triticum aestivum L.) that has two or three pistils and three stamens. The multi-ovary trait is controlled by a dominant gene, the expression of which can be suppressed by the special heterogeneous cytoplasm of line TeZhiI (TZI). TZI has the nucleus of common wheat and the cytoplasm of Aegilops. DUOII (♀) × TZI (♂) shows the multi-ovary trait, whereas TZI (♀) × DUOII (♂) shows the mono-ovary trait. DNA methylation affects gene expression and plays a crucial role in organ and tissue differentiation. In order to study the relationship between DNA methylation and the suppression of the multi-ovary gene, we used methylation-sensitive amplification polymorphisms (MSAP) to assess the DNA methylation status of the reciprocal crosses. Genome-wide, 14 584 CCGG sites were detected and the overall methylation levels were 31.10% and 30.76% in the respective crosses DUOII × TZI and TZI × DUOII. Compared with DUOII × TZI, TZI × DUOII showed 672 sites (4.61%) in which methylation–demethylation processes occurred. The results showed that the special heterogeneous cytoplasm significantly changed DNA methylation, and this might have suppressed the multi-ovary gene. The results provide insight into the changing patterns of DNA methylation in the suppression of the multi-ovary gene, and provide essential background for further studies on the underlying mechanisms of heterogeneous cytoplasm suppression of the expression of the multi-ovary gene in wheat.


Epigenomics ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1413-1427 ◽  
Author(s):  
Zachary M Laubach ◽  
Wei Perng ◽  
Andres Cardenas ◽  
Sheryl L Rifas-Shiman ◽  
Emily Oken ◽  
...  

Aim: We investigated associations of prenatal socioeconomic status (SES) with DNA methylation at birth, and to explore persistence of associations into early (∼3 years) and mid-childhood (∼7 years) among 609 mother–child pairs in a Boston-area prebirth cohort. Materials & methods: First, we created a prenatal SES index comprising individual- and neighborhood-level metrics and examined associations of low (lowest 10%) versus high (upper 90%) SES with genome-wide DNA methylation in cord blood via the Infinium HumanMethylation450 BeadChip. Next, we evaluated persistence of associations detected in cord blood with DNA methylation of the same CpG sites measured in peripheral leukocytes in early- and mid-childhood. Results & conclusion: Low prenatal SES was associated with methylation at CpG sites near ACSF3, TNRC6C-AS1, MTMR4 and LRRN4. The relationship with LRRN4 persisted into early childhood.


2021 ◽  
Vol 51 ◽  
pp. e15-e16
Author(s):  
Brooke Smith ◽  
Alexandre Lussier ◽  
Janine Cerutti ◽  
Esther Walton ◽  
Andrew Simpkin ◽  
...  

2017 ◽  
Author(s):  
Gabriel Cuellar Partida ◽  
Charles Laurin ◽  
Susan M. Ring ◽  
Tom R. Gaunt ◽  
Caroline L. Relton ◽  
...  

AbstractGenomic imprinting is an epigenetic mechanism leading to parent-of-origin dependent gene expression. So far, the precise number of imprinted genes in humans is uncertain. In this study, we leveraged genome-wide DNA methylation in whole blood measured longitudinally at 3 time points (birth, childhood and adolescence) and GWAS data in 740 Mother-Child duos from the Avon Longitudinal Study of Parents and Children (ALSPAC) to systematically identify imprinted loci. We reasoned that cis-meQTLs at genomic regions that were imprinted would show strong evidence of parent-of-origin associations with DNA methylation, enabling the detection of imprinted regions. Using this approach, we identified genome-wide significant cis-meQTLs that exhibited parent-of-origin effects (POEs) at 35 novel and 50 known imprinted regions (10−10< P <10−300). Among the novel loci, we observed signals near genes implicated in cardiovascular disease (PCSK9), and Alzheimer’s disease (CR1), amongst others. Most of the significant regions exhibited imprinting patterns consistent with uniparental expression, with the exception of twelve loci (including the IGF2, IGF1R, and IGF2R genes), where we observed a bipolar-dominance pattern. POEs were remarkably consistent across time points and were so strong at some loci that methylation levels enabled good discrimination of parental transmissions at these and surrounding genomic regions. The implication is that parental allelic transmissions could be modelled at many imprinted (and linked) loci and hence POEs detected in GWAS of unrelated individuals given a combination of genetic and methylation data. Our results indicate that modelling POEs on DNA methylation is effective to identify loci that may be affected by imprinting.


2021 ◽  
Author(s):  
Brooke J. Smith ◽  
Alexandre A Lussier ◽  
Janine Cerutti ◽  
Daniel J. Schaid ◽  
Andrew J. Simpkin ◽  
...  

Background: Exposure to adversity during childhood is estimated to at least double the risk of depression later in life. Some evidence suggests childhood adversity may have a greater impact on depression risk, if experienced during specific windows of development called sensitive periods. During these sensitive periods, there is evidence that adversity may leave behind biological memories, including changes in DNA methylation (DNAm). Here we ask if those changes play a role in the link between adversity and later adolescent depressive symptoms. Methods: We applied a method for high-dimensional mediation analysis using data from a subsample (n=627-675) of the Avon Longitudinal Study of Parents and Children. We first assessed the possibility of time-dependent relationships between seven types of childhood adversity (caregiver abuse, physical/sexual abuse, maternal psychopathology, one-adult household, family instability, financial stress, neighborhood disadvantage), measured on at least four occasions between ages 0-7 years, and adolescent depression at mean age 10.6. Specifically, we considered three types of life course hypotheses (sensitive periods, accumulation, and recency), and then evaluated which of these hypotheses had the strongest association in each adversity-adolescent depression relationship using the structured life course modeling approach (SLCMA; pronounced slick-mah). To conduct the mediation analyses, we used a combination of pruning and sure independence screening (a dimension reduction method) to reduce the number of methylated CpG sites under consideration to a viable subset for our sample size. We then applied a sparse group lasso penalized model to identify the top mediating loci from that subset using the combined strength of the coefficient measuring the relationship between the childhood adversity and a CpG site (α) and of the coefficient measuring the relationship between the CpG site and depressive symptoms (β) as a metric. Using a Monte Carlo method for assessing mediation (MCMAM), we assigned a significance level and confidence interval to each identified mediator. Results: Across all seven adversities, we identified a total of 70 CpG sites that showed evidence of mediating the relationship between adversity and adolescent depression symptoms. Of these 70 mediators, 37 were significant at the p < 0.05 level when applying the MCMAM, a method tailored to estimating the significance of SEM-derived mediation effects. These sites exhibited four different mediating patterns, differentiated by the direction of α and β. These patterns had signals that were: (1) both positive (19 loci), (2) both negative (18 loci), (3) positive α and negative β (23 loci) or (4) negative α and positive β (10 loci). Conclusion: Our results suggest that DNAm partially mediates the relationship between different types of childhood adversity and depressive symptoms in adolescence. These findings provide insight into the biological mechanisms that link childhood adversity to depression, which will ultimately help develop treatments to prevent depression in more vulnerable populations.


2016 ◽  
Author(s):  
Daniel L. McCartney ◽  
Rosie M. Walker ◽  
Stewart W. Morris ◽  
Andrew M. McIntosh ◽  
David J. Porteous ◽  
...  

AbstractGenome-wide analysis of DNA methylation has now become a relatively inexpensive technique thanks to array-based methylation profiling technologies. The recently developed Illumina Infinium MethylationEPIC BeadChip interrogates methylation at over 850,000 sites across the human genome, covering 99% of RefSeq genes. This array supersedes the widely used Infinium HumanMethylation450 BeadChip, which has permitted insights into the relationship between DNA methylation and a wide range of conditions and traits. Previous research has identified issues with certain probes on both the HumanMethylation450 BeadChip and its predecessor, the Infinium HumanMethylation27 BeadChip, which were predicted to affect array performance. These issues concerned probe-binding specificity and the presence of polymorphisms at target sites. Using in silico methods, we have identified probes on the Infinium MethylationEPIC BeadChip that are predicted to (i) measure methylation at polymorphic sites and (ii) hybridise to multiple genomic regions. We intend these resources to be used for quality control procedures when analysing data derived from this platform.


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