THE LINQUISTIC PHENOTYPE IN FAMILIA DYSLEXIA

拟议研究的重点是继续基因型和 常染色体显性遗传家系的表型研究 阅读障碍的显性遗传 诵读困难与 染色体15标记在这些家庭中的一些，但不是在 其他的，表明遗传异质性。 该项目的具体长期目标是（1）更多 精确地绘制了15号染色体上的阅读障碍基因座， 评估是否有第二个主要的阅读障碍位点， 家族中的另一条染色体不与15号染色体连锁;（2） 为了阐明语言学的发展， 阅读障碍者阅读过程的表型和成分 （3）检测表型差异 在基因型不同的阅读障碍之间;以及（4）确定 潜在的语言表型是否具有连续性 从学龄前到成年，如果是这样，为了确定这是如何发生的， 潜在的缺陷会影响不同年龄段的阅读过程。 由于发展研究的独特优势， 具有共同病因的阅读障碍家族，建议进行研究 将更清晰地描绘出 比以前可能的寿命更长。 实现这些目标将导致一个更清晰、科学的 了解一个（或多个）主基因对一个 人类认知中具有文化意义的特殊方面。 在临床上，这样的理解将形成一个良好的基础- 早期识别和治疗的方法 常见的发育障碍 为实现这些目标而提出的方法 包括（1）继续研究新旧 与Shelley Smith和Bill Kimberling合作， 奥马哈;（2）一项对两个潜在的 语言表型和阅读过程的组成部分 来自这些家庭的青少年和儿童阅读障碍者;以及（3）a 语言表型的纵向研究 学龄前儿童，以确定这种表型的哪一方面是 最能预测这些高危家庭日后的阅读障碍。

The focus of the proposed research is continued genotype and phenotype studies of families who demonstrate autosomal dominant transmission of dyslexia. Dyslexia is linked to chromosome 15 markers in some of these families, but not in others, indicating genetic heterogeneity. The specific long-term objectives of this project are (1) to more precisely map the dyslexia locus on chromosome 15 and to evaluate whether there is a second major dyslexia locus on another chromosome in families not linked to chromosome 15; (2) to clarify the development of both the underlying linguistic phenotype and components of the reading process in dyslexics from these families; (3) to test for any phenotypic differences between genotypically different dyslexics; and (4) to determine whether there is continuity in the underlying linguistic phenotype from preschool to adulthood, and, if so, to determine how this underlying deficit affects reading processes at different ages. Because of the unique advantages of developmental studies within dyslexic families with a common etiology, the proposed research will yield a much clearer picture of dyslexic development across the life-span than has previously been possible. Achieving these objectives will lead to a clearer, scientific understanding of the effects of one (or more) major genes on a specific and culturally significant aspect of human cognition. Clinically, such an understanding will form the basis of a well- grounded approach to early identification and treatment of this common developmental disorder. The methodology that is proposed to meet these objectives consists of (1) continued linkage studies of both old and new families in collaboration with Shelley Smith and Bill Kimberling in Omaha; (2) a cross-sectional study of both the underlying linguistic phenotype and the components of the reading process in adolescent and child dyslexics from these families; and (3) a longitudinal study of the underlying linguistic phenotype in preschool children to determine which aspect of this phenotype is most predictive of later dyslexia in these high-risk families.