The Linguistic Phenotype in Familial Dyslexia

描述（由申请人提供）：拟议研究的总体目标是了解语音障碍（SSD）和阅读障碍（RD）之间的共病。实现这一目标将有助于我们理解口语和书面语发展之间的关系。尽管表面上存在差异，但事实证明，SSD和RD是家族性的、连贯的，并且在语音发展方面存在共同的缺陷。但SSD与RD的共病性并不完全，因为有些患有SSD的儿童没有发生RD，而有些患有RD的儿童从未使用过SSD。因此，每一种疾病都必须有特定的病因和认知风险因素，这项拟议的研究也试图确定这些因素。我们将继续使用分子方法来确定哪些遗传风险因素是SSD和RD共有的，哪些是特异性的，我们还将研究环境风险和保护因素对这些疾病的贡献。为了增加分子分析的能力，我们正在为150个家庭和至少180对同胞对的总样本额外招募85对独立的同胞对。为了了解哪些认知风险因素是SSD和RD共有的，哪些是特定的，我们将完成一项正在进行的纵向研究，对111名患有SSD的学龄前先证儿童和41名年龄、性别和社会地位相似的对照组进行研究，并在5岁（开始识字教学之前）和8岁（识字发展早期）这两个时间点添加RD儿童的横断面样本。完成这项纵向研究将使我们能够确定有多少SSD先证发展为RD，并直接测试哪些认知缺陷是SSD和RD共同的，哪些是在早期读写能力发展的不同阶段特定的。

DESCRIPTION (provided by applicant): The overall goal of the proposed research is to understand the comorbidity between speech sound disorder (SSD) and reading disability (RD). Accomplishing this goal will help us understand the relation between spoken and written language development. Despite their surface differences, it turns out that SSD and RD are co-familial, coheritable, and share a deficit in phonological development. But the comorbidity between SSD and RD is not complete because there are some children with SSD who do not develop RD and some children with RD who never had SSD. Hence, there must also be both etiological and cognitive risk factors that are specific to each disorder, which the proposed research also seeks to identify. We will continue to use molecular methods to specify which genetic risk factors are shared by SSD and RD and which are specific, and we will also examine the contribution of environmental risk and protective factors to these disorders. To increase the power of the molecular analyses, we are recruiting an additional 85 independent sib pairs for a total sample of 150 families and at least 180 sib pairs. To understand which cognitive risk factors are shared by SSD and RD and which are specific, we will complete an ongoing longitudinal study of 111 preschool probands with SSD, and 41 controls similar in age, gender, and SES, adding cross-sectional samples of RD children at both time points: age 5 (before the onset of literacy instruction) and age 8 (early in literacy development). Completing this longitudinal study will allow us to determine how many SSD probands develop RD and to test directly which cognitive deficits are shared by SSD and RD and which are specific at different points in early literacy development.