Epigenetic Marks as Peripheral Biomarkers of Autism

描述（由申请人提供）：自闭症谱系障碍（ASD）是一种常见的表型，具有复杂的病因。虽然罕见的单个基因或基因组间隔可能足以导致ASD，但大多数患者可能将其疾病归因于遗传和环境变异的结合。连接遗传和环境影响的一个领域是表观遗传变异。为了寻找ASD特异性表观遗传变异的证据，我们筛选了49名ASD男性和他们未受影响的父亲，检测了对应于807个基因的1,505个CpG二核苷酸的甲基化状态。使用33对作为训练集和16对作为验证集，我们统计确定了116个差异甲基化基因座（DML），这些基因座对ASD男孩与其父亲的分类具有最高的预测能力。使用这些DML，我们以盲法筛选了从另外29对ASD儿子/未受影响的父亲对的全血中分离的DNA，并正确分类了约80%的ASD受影响的个体。我们使用亚硫酸氢盐测序验证了这些位点的一个子集，并排除了年龄依赖性效应。为了跟进这一非凡的观察结果，我们在这里建议进行一项全面的全基因组甲基化分析，该分析将询问与300个ASD Simons Simplex 4人家庭（父亲，母亲和不和谐的男性同胞对）全血中分离的DNA中超过14，000个基因相关的27，578个CpG二核苷酸。使用这些数据，我们将构建一个较小的自定义DML集，并筛选另外900名ASD先证者及其家族。该分析将直接测试我们的挑衅性初步数据，并可能识别可能损害ASD外周生物标志物测定的DML。 公共卫生相关性：自闭症是一种常见的疾病，其原因知之甚少。遗传和环境的影响被认为共同作用导致自闭症。表观遗传学是一个连接遗传和环境影响的领域，通常通过检查DNA的动态甲基化变化来研究。我们用这种方法在807个基因中筛选了78名自闭症男孩和他们的父亲，发现了116个甲基化变化，这些变化加在一起可以正确识别出近80%的自闭症男孩和他们的父亲。我们建议在1，200名自闭症男孩及其家人（包括未受影响的兄弟）的更大基因组中证实这些令人兴奋的数据。这些数据不仅可以为自闭症的病因提供新的见解，而且还可能导致自闭症的筛查测试。)

DESCRIPTION (provided by applicant): Autism spectrum disorders (ASD) are a common phenotype with a complex etiology. While a rare single gene or genomic interval may be sufficient to lead to ASD, most patients likely owe their disease to a combination of both genetic and environmental variation. One area that bridges genetic and environmental influences is epigenetic variation. Seeking evidence for epigenetic variation specific to ASD, we screened 49 ASD males and their unaffected fathers for methylation status of 1,505 CpG dinucleotides corresponding to 807 genes. Using 33 pairs as a training set and 16 pairs as a validation set, we statistically identified 116 differentially methylated loci (DML) that gave the highest predictive power to classify ASD boys from their fathers. Using these DML, we screened, in a blinded fashion, DNA isolated from whole blood in an additional 29 ASD son/unaffected father pairs and correctly classified ~80% of the ASD affected individuals. We validated a subset of these loci using bisulfite sequencing and ruled out age-dependent effects. To follow-up on this extraordinary observation, we propose here to conduct a comprehensive genome-wide methylation analysis that will interrogate 27,578 CpG dinucleotides associated with more than 14,000 genes in DNA isolated from whole blood in 300 ASD Simons Simplex 4-person families (father, mother and discordant male sib pair). Using this data, we will then construct a smaller custom set of DML and screen an additional 900 ASD probands and their families. This analysis will directly test our provocative preliminary data and potentially identify DML that could compromise a peripheral biomarker assay for ASD. PUBLIC HEALTH RELEVANCE: Autism is a common disorder whose causes are poorly understood. Both genetic and environmental influences are thought to act together causing autism. Epigenetics is an area that bridges genetic and environmental influencing and commonly is studied by examining dynamic methylation changes to the DNA. We have screened a total of 78 autistic boys and their fathers by this method in 807 genes and find 116 methylation changes that together can correctly identify nearly 80% of the affected boys from their fathers. We propose to confirm these exciting data in a much larger set of genes in 1,200 autistic boys and their families, including unaffected brothers. These data not only could provide new insight into the causes of autism but could also result in a screening test for autism. )