Grammatical Development in Boys with Fragile X Syndrome and Autism

描述（申请人提供）：脆性X综合征是智力残疾的主要遗传原因，大多数男性（95%）智商低于70。大多数患有脆性X染色体的男性表现出类似自闭症的行为，25-30%符合DSM-IV的自闭症联合诊断标准。患有脆性X染色体和自闭症的男性通常在认知和接受/表达语言方面有更严重的整体损伤。然而，仅在脆性X和共病性脆性X和自闭症中，语言表型在个体之间是非常不同的。此外，自闭症对脆性X语言表型的影响尚不清楚。拟议项目的目的是确定FXS和自闭症中是否存在语法缺陷，同时检查共病自闭症对脆性x语言的影响。迄今为止，关于发育障碍语言发展的研究本质上是描述性的，而不是理论驱动的。然而，在语言障碍儿童的语法发展方面，有一个丰富的理论驱动的研究路线。扩展可选不定式解释（EOI）认为，患有特殊语言障碍的儿童似乎陷入了可选不定式阶段，在这个阶段，他们将某些语法语素的使用视为可选的，尽管它们在成人语法中是强制性的。初步证据表明，患有脆性X染色体的儿童和患有自闭症的儿童可能在语法发展的至少一个方面表现出缺陷（即，有限标记；过去时：他走路），独立于非语言智商。该项目将通过检查所有限定性标记（BE/DO）以及非限定性语法语素（即复数-s，所有格-s，现在进行式-ing）来推进初步工作。这项调查将揭示患有脆性X的男孩是否表现出与特殊语言障碍相似的语法特征，或者他们的语言是否具有所有语法语素的整体困难。此外，还将通过比较患有和不患有自闭症的脆性X染色体男孩和患有特发性自闭症的男孩来研究共病自闭症对语法发展的影响。此外，拟议的研究将研究评估FXS男孩和自闭症男孩语法的最有效方法。本次研究将有63名年龄在9-16岁之间的男孩参加：仅患有FXS的男孩，患有FXS和自闭症的男孩，以及患有特发性自闭症的男孩。参与者将完成标准化测试、语言样本、自闭症诊断测量和句子模仿任务。这些结果将为脆性X染色体和自闭症的表型提供信息，并为不同病因条件下语言障碍的变异性本质提供见解。从这些研究中获得的信息将提供(1)关于语言发展的神经约束的假设，以及(2)临床评估和干预程序。这项研究为未来评估语言系统其他方面的研究奠定了基础。

DESCRIPTION (provided by applicant): Fragile X syndrome is the leading inherited cause of intellectual disability, with the majority of males (95%) having IQs below 70. Most males with fragile X display autistic-like behaviors, and 25-30% meet the DSM-IV criteria for an autism co-diagnosis. Males with comorbid fragile X and autism are typically reported to have more severe overall impairments in cognition and receptive/expressive language. However, the language phenotype within fragile X only and comorbid fragile X and autism is extremely variable across individuals. Moreover, the impact of autism on the language phenotype of fragile X is not clear. The purpose of the proposed project is to determine if there is a grammatical deficit in FXS and in autism, while examining the consequences of comorbid autism on language in fragile X. Research on language development in developmental disabilities to date has been descriptive in nature, as opposed to theory-driven. There is however, a rich theory-driven line of research on grammatical development in children with language impairments. The extended optional infinitive account (EOI) posits that children with specific language impairment seem to get "stuck" in an optional infinitive stage in which they treat the use of certain grammatical morphemes as optional, despite their obligatory status in the adult grammar. Preliminary evidence suggests that children with fragile X and children with autism may demonstrate a deficit in at least one aspect of grammatical development (i.e., finiteness marking; past tense: he walked) independent of nonverbal IQ. This project will advance preliminary work by examining all finiteness markers (BE/DO), as well as non-finiteness grammatical morphemes (i.e., plural -s, possessive -s, present progressive -ing). This investigation will inform whether boys with fragile X show a grammatical profile similar to SLI, or if their language is characterized by global difficulty with all grammatical morphemes. In addition, the impact of co-morbid autism on grammatical development will be examined by comparing boys with fragile X with and without autism and boys with idiopathic autism. Additionally, the proposed study will examine the most effective method of assessing grammar in boys with FXS and boys with autism. Sixty-three boys between the ages of 9-16 years will participate in this study: boys with FXS only, boys with FXS and autism, and boys with idiopathic autism. Participants will complete standardized tests, a language sample, autism diagnostic measures, and a sentence imitation task. These results will inform the phenotypes of fragile X and autism and provide insights into the nature of variability in language impairments across different etiological conditions. The information from the proposed studies will inform (1) hypotheses regarding neural constraints on language development as well as (2) clinical assessment and intervention procedures. This study lays the groundwork for future studies needed to assess additional aspects of the linguistic system.