Environment, The Perinatal Epigenome, and Risk for Autism and Related Disorders

项目摘要 自闭症谱系障碍（ASD）和相关的发育表型是在终身挑战和家庭成本方面最具破坏性的儿童疾病之一。我们建议测试的假设，自闭症和相关疾病有一个表观遗传的基础。我们挑战自闭症的标准遗传范式是不完整的，并认为怀孕期间的环境因素在这种疾病中起着关键作用，这些都是由表观遗传机制介导的。我们提出了一个实质性的 自闭症和相关疾病的病因学的新方法，通过对从怀孕开始到新生儿生命的最初几年的前瞻性数据进行一系列渐进的流行病学分析，整合遗传，表观遗传和环境信息。我们已经合作了两个互补的怀孕队列：1）早期自闭症风险纵向调查（EARLI）网络，该网络正在招募具有ASD新生儿高风险的孕妇，因为他们已经患有ASD 一名自闭症儿童，2）约翰霍普金斯大学国家儿童研究中心，该中心正在马里兰州的两个县招募有代表性的孕妇。总之，这些队列收集了800名母亲、父亲和儿童在怀孕期间和出生后的大量数据，包括：母亲在怀孕期间至少两次、出生时和12个月时的儿童、父亲在怀孕期间的生物样本以及300个胎盘;记录的多次孕前和子宫内暴露和/或 直接测量;评估与出生时（胎龄、出生体重和头围）和12个月时（语言、社交、认知技能）测量的ASD相关的儿童发育特征。 我们将对这些生物样本进行全基因组甲基化和等位基因特异性表达分析，以解决以下问题：1）表观基因组中是否存在易受妊娠前和妊娠期间环境损伤影响的区域？2)表观基因组中是否存在与ASD相关的定量新生儿和婴儿发育表型相关的区域？3)遗传变异如何影响这些表观遗传学发现？我们的方法的主要特征包括a）新的全基因组表观遗传阵列和统计方法，B）两个互补的妊娠队列，c）通过妊娠和早期生活的纵向表观基因组分析，d）通过妊娠的暴露测量，e）出生和早期生活的定量发育特征，以及f）GWAS与表观基因组数据的整合。这项工作将作为“表观遗传流行病学”新领域的基础，并代表了一个非凡的机会来测试遗传学，表观遗传学和环境在怀孕前和怀孕期间相互作用，以调节破坏性和常见疾病的风险，使用最先进的流行病学和表观基因组设计。它将首次对人类表观基因组中的先天和后天之间的关系进行严格的分析。

PROJECT SUMMARY Autism spectrum disorders (ASD) and related developmental phenotypes are among the most devastating of childhood disorders in terms of lifetime challenges and costs to families. We propose to test the hypothesis that autism and related disorders have an epigenetic basis. We challenge the standard genetic paradigm for autism as incomplete and argue that environmental factors during pregnancy play a critical role in the disorder and that these are mediated by epigenetic mechanisms. We propose a substantially new approach to the etiology of autism and related disorders that integrates genetic, epigenetic, and environmental information through a series of progressive epidemiologic analyses of prospective data beginning at the onset of pregnancy, through the first years of the newborn's life. We have partnered two complementary pregnancy cohorts: 1) the Early Autism Risk Longitudinal Investigation (EARLI) Network, which is recruiting pregnant women at high risk of having a new child with ASD because they already have an autistic child, 2) the Johns Hopkins University National Children's Study site, which is recruiting representative pregnancies in two Maryland counties. Together, these cohorts an extraordinary wealth of data across pregnancy and postnatally in 800 mothers, fathers, and children including: biosamples from mothers at least twice during pregnancy, from children at birth and 12 months, from fathers during the pregnancy, and from 300 placenta; multiple pre-conception and in utero exposures documented and/or directly measured; assessment of child development features associated with ASDs measured at birth (gestational age, birth weight and head circumference) and at 12 months (language, social, cognitive skills). We will perform genome-wide methylation and allele-specific expression analyses on these biosamples to address the following questions: 1) Are there regions of the epigenome that are susceptible to environmental insults occurring before and during pregnancy?; 2) Are there regions of the epigenome that correlate with quantitative newborn and infant developmental phenotypes related to ASD?; 3) How does genetic variation influence these epigenetic findings? The major features of our approach include a) novel genome-wide epigenetic array and statistical methods, b) two complementary pregnancy cohorts, c) longitudinal epigenome analysis through pregnancy and early life, d) exposure measurements through pregnancy, e) quantitative developmental traits at birth and in early life, and f) integration of GWAS with epigenome data. This work will serve as a foundation for a new field of "Epigenetic Epidemiology" and represents an extraordinary opportunity to test the idea that genetics, epigenetics and environment interact before and through pregnancy to modulate the risk of a devastating and common disease, using a state-of-the-art epidemiological and epigenomic design. It will provide the first rigorous analysis of the relationship between nature and nurture in the human epigenome.