Niemitz, E. L., & Feinberg, A. P. (2004). Epigenetics and assisted reproductive technology: a call for investigation. American journal of human genetics, 74(4), 599-609. https://doi.org/10.1086/382897
Niemitz EL, Feinberg AP. Epigenetics and assisted reproductive technology: a call for investigation. Am J Hum Genet. 2004;74(4):599-609. doi:10.1086/382897
Niemitz, Emily L., and Andrew P. Feinberg. "Epigenetics and assisted reproductive technology: a call for investigation." American journal of human genetics, vol. 74, no. 4, 2004, pp. 599-609.
Predoctoral Program in Human Genetics and Epigenetics Unit, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Linked to ROR, the Research Organization Registry
Abstract
A surprising set of recent observations suggests a link between assisted reproductive technology (ART) and epigenetic errors--that is, errors involving information other than DNA sequence that is heritable during cell division. An apparent association with ART was found in registries of children with Beckwith-Wiedemann syndrome, Angelman syndrome, and retinoblastoma. Here, we review the epidemiology and molecular biology behind these studies and those of relevant model systems, and we highlight the need for investigation of two major questions: (1) large-scale case-control studies of ART outcomes, including long-term assessment of the incidence of birth defects and cancer, and (2) investigation of the relationship between epigenetic errors in both offspring and parents, the specific methods of ART used, and the underlying infertility diagnoses. In addition, the components of proprietary commercial media used in ART procedures must be fully and publicly disclosed, so that factors such as methionine content can be assessed, given the relationship in animal studies between methionine exposure and epigenetic changes.
There is an increased incidence of rare imprinting disorders associated with assisted reproduction technologies (ARTs). The identification of epigenetic changes at imprinted loci in ART infants has led to the suggestion that the techniques themselves may predispose embryos to acquire imprinting errors and diseases. However, it is still unknown at what point(s) these imprinting errors arise, or the risk factors. In 2009 we conducted a Japanese nationwide epidemiological study of four well-known imprinting diseases to determine any association with ART. Using bisulfite sequencing, we examine the DNA methylation status of 22 gametic differentially methylated regions (gDMRs) located within the known imprinted loci in patients with Beckwith-Wiedemann syndrome (BWS, n=1) and also Silver-Russell syndrome (SRS, n= 5) born after ART, and compared these with patients conceived naturally. We found a 10-fold increased frequency of BWS and SRS associated with ART. The majority of ART cases showed aberrant DNA methylation patterns at multiple imprinted loci both maternal and paternal gDMRs (5/6), with both hyper- and hypomethylation events (5/6) and also mosaic methylation errors (5/6). Although our study may have been limited by a small sample number, the fact that many of the changes were mosaic suggested that they occurred after fertilization. In contrast, few of the patients who were conceived naturally exhibited a similar pattern of mosaic alterations. The differences in methylation patterns between the patients who were conceived naturally or after ART did not manifest due to the differences in the disease phenotypes in these imprinting disorders. A possible association between ART and BWS/SRS was found, and we observed a more widespread disruption of genomic imprints after ART. The increased frequency of imprinting disorders after ART is perhaps not surprising given the major epigenetic events that take place during early development at a time when the epigenome is most vulnerable.
Uyar A et al., 2014·Current Opinion in Obstetrics & Gynecology·Free full text on PubMed Central
Purpose of reviewGenomic imprinting refers to preferential allele-specific gene expression. DNA methylation-based molecular mechanisms regulate establishment and maintenance of parental imprints during early embryo development and gametogenesis. Because of the coincident timing, a potential association between assisted reproductive technology (ART) procedures and imprinting defects has been investigated in various studies. In this review, we provide an overview of genomic imprinting and present a summary of the relevant clinical data. Recent findings: ART procedures affect DNA methylation pattern, parental imprinting status, and imprinted gene expression in the mouse embryo. In humans, several case series suggested an association between ART and imprinting disorders, with a three-fold to six-fold higher prevalence of ART use among children born with Beckwith-Wiedemann syndrome compared to the general population. However, more recent studies failed to support these findings and could not demonstrate an association between imprinting disorders and ARTs, independent of subfertility. ART procedures may affect methylation status of imprinted regions in the DNA, leading to imprinting disorders. Although the low prevalence of imprinting disorders makes it challenging to perform conclusive clinical trials, further studies in large registries are required to determine the real impact of ARTs on their occurrence.
Kochanski A et al., 2013·Journal of Neonatal-Perinatal Medicine
The question of genetic alterations resulting from assisted reproductive technologies (ART) in humans is examined within the organization of the human genome. Increased rates of birth defects have been reported among children conceived using ART; however, questions remain and controversy exists regarding how "infertility" predisposes to birth defects. ART has been shown to be associated with an increased number of chromosomal alterations especially in the X chromosome. There is increased risk for embryonal tumors among ART conceived children, as well as, imprinting disorders (Beckwith-Wiedemann and Angelman Syndromes). Genetic studies of children conceived using ART reveal a larger (genome-wide) scale of methylation defects that encompass hundreds of genes. Genes involved in carcinogenesis and developmental pathways appear altered and may impact on later development of chronic illness, although these data are very preliminary. ART may create novel mutations by different chromosomal and molecular mechanisms; however, these techniques also enable propagation of pre-existing mutations that are associated with impaired fertility. While older maternal age is often associated with female infertility and chromosomal aneuploidy, sperm from older men have more new gene mutations. The prevalence of birth defects is increased when ART is used for conception. These data are summarized by large meta-analyses or from multi-year national registries. Whether the increased number of birth defects is due to ART procedures themselves or are a consequence of the impaired fertility of the parents is discussed. Long-term evaluation of children conceived using ART and/or ovarian hyper-stimulation is needed to determine whether alterations during embryonic development may increase the prevalence of chronic diseases in adulthood.
Increasing numbers of children are being conceived by assisted reproductive technology (ART). A number of studies have highlighted an altered epigenetic status in gametes from infertile couples and the possibility of an increased risk of imprinting defects and somatic epigenetic changes in ART conceived children, but the results have been heterogeneous. We performed a systematic review of existing studies to compare the incidence of imprinting disorders and levels of DNA methylation in key imprinted genes in children conceived through in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) with those in children conceived spontaneously. A detailed search strategy was used to conduct electronic literature searches (spanning 1978 to 2013) on Medline, EMBASE, the Cochrane Library and Web of Science. Abstracts of relevant conference papers were identified. As randomized trials are not feasible in this context, we included observational (cohort and case-control) studies comparing outcomes in children conceived through ART with those conceived spontaneously, irrespective of the language of publication. The outcome measures were DNA methylation and the incidence of imprinting disorders. A total of 351 publications were identified by the initial search. Of these, 26 were excluded as duplicates and 241 were excluded after reviewing the abstracts, then of those remaining 66 were excluded after review of the full text. A total of 18 papers were included in the review. Apart from one case-control study, all were cohort studies. There was a degree of clinical heterogeneity in terms of the study population, type of infertility treatment, and samples obtained from exposed and unexposed children. DNA methylation levels were either presented as categorical data (hypo-, hyper- or normally methylated DNA) or continuous data (i.e. percentage of methylated DNA). The combined odds ratio (95% confidence intervals) of any imprinting disorder in children conceived through ART was 3.67 (1.39, 9.74) in comparison with spontaneously conceived children. Meta-analysis of data from relevant studies revealed that the weighted mean difference (95% confidence intervals) in methylation percent between IVF/ICSI versus spontaneously conceived children were as follows: H19: -0.46(-1.41, 0.49), PEG1-MEST: 0.47 (-2.07, 3.01), GRB10: -0.05 (-0.43, 0.33), IGF2: -0.15 (-1.09, 0.79), -0.55 (-1.55, 0.46), KvDMR/KCNQ10T1: -0.16 (-0.34, 0.02) and PEG3: -0.24 (-1.72, 1.24). There was an increase in imprinting disorders in children conceived though IVF and ICSI but insufficient evidence for an association between ART and methylation in other imprinted genes. Heterogeneity in the types of fertility treatment, the imprinted regions studied, the tissues used and the methods of measurement, reduce our ability to assess the full effect of ART on DNA methylation and imprinting. More controlled studies, using standardized methodologies, in larger, better clinically defined populations are needed.
Assisted Reproduction › Safety and Risks › Birth Defects
Andrew P Feinberg, Emily L Niemitz
Andy Feinberg, Drew Feinberg, A Feinberg, E Niemitz
PMID 14991528 14991528 DOI 10.1086/382897 10.1086/382897 Niemitz et al. 2004, Niemitz 2004
Cite this article
Niemitz, E. L., & Feinberg, A. P. (2004). Epigenetics and assisted reproductive technology: a call for investigation. American journal of human genetics, 74(4), 599-609. https://doi.org/10.1086/382897
Niemitz EL, Feinberg AP. Epigenetics and assisted reproductive technology: a call for investigation. Am J Hum Genet. 2004;74(4):599-609. doi:10.1086/382897
Niemitz, Emily L., and Andrew P. Feinberg. "Epigenetics and assisted reproductive technology: a call for investigation." American journal of human genetics, vol. 74, no. 4, 2004, pp. 599-609.
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