A California Population-Based Twin Study of Autism

描述（由申请人提供）：在所有多因素儿童精神障碍中，自闭症是最强烈的遗传影响。遗传的责任并不局限于自闭症的全部临床综合征，而是包括一系列的行为和认知特征。家族研究未能区分自闭症福尔斯的遗传易感性是否属于连续的严重程度谱，或者是否可以更好地细分为不同的分类亚型。从遗传学的角度来看，这提出了一个问题，自闭症表型的不同方面是否受到不同基因座的影响。 这项拟议中的研究将是最大的，基于人群的自闭症双胞胎研究。有了这个独特的样本，我们将能够解开基因和环境之间的关系，因为它与自闭症谱系障碍儿童的认知障碍和临床症状有关。我们将使用（a）自闭症样行为的临床指标（B）重复和刻板行为的更具体指标（c）一般认知能力指标（d）更具体的神经认知能力指标来评估双胞胎对。 这将使我们能够解决几个基本问题：（1）自闭症的遗传性是什么？（2）遗传因素对症状变化的贡献是什么？(3)在定量神经认知特征和临床障碍之间是否存在连续性？(4)遗传和非遗传因素在神经认知特征的变异中占多大比例？

DESCRIPTION (provided by applicant): Of all multifactorial child psychiatric disorders, autism is the most strongly genetically influenced. The inherited liability is not restricted to the full clinical syndrome of autism but encompasses a range of behavioral and cognitive characteristics. Family studies have failed to distinguish whether the genetic liability to autism falls on a continuous spectrum of severity or whether it may be better subdivided into distinct categorical subtypes. From a genetic standpoint this raises the question, whether different aspects of the autism phenotype are influenced by different loci. The proposed study will be the largest, population-based study of twins with autism. With this unique sample we will be able to unravel the relationship between genes and environment as it pertains to the cognitive impairments and the clinical symptoms seen in children with autism spectrum disorders. We will assess twin pairs using (a) clinical measures of autistic-like behaviors (b) more specific measures for repetitive and stereotyped behaviors, (c) measures of general cognitive ability d) measures of more specific neurocognitive abilities. This will allow us to address several fundamental questions: (1) what is the heritability of autism (2) what is the contribution of genetic factors to variation in symptom dimensions? (3) is there a continuum between the quantitative neurocognitive traits and clinical disorder? (4) what proportion of the variance in the neurocognitive traits is accounted for by genetic and non-genetic factors?