Department of Psychology, Florida State University, Tallahassee, FL, USA.
J Dev Behav Pediatr. 2010 Sep;31(7):525-32. doi: 10.1097/DBP.0b013e3181ee4b70.
Dyslexia is a prominent focus of practitioners, educators, and researchers because of the myriad consequences of failing to read proficiently. The aim of this study was to provide a brief overview of how twin studies can offer insight on the cause of many human behaviors and disorders including dyslexia, discuss common misconceptions regarding findings from behavioral genetic studies, briefly review the evidence on the relationship between genes, environment, and dyslexia, and finally present some findings from a large-scale twin study on reading and dyslexia.
Participants were twins from a large ethnically and socioeconomically diverse twin sample in an ongoing longitudinal study of reading and dyslexia. Heritabilities of reading ability and dyslexia were calculated for 1,024 first grade twins on a standardized reading measure. Children were identified as dyslexic if they scored at the 15th percentile or below on a reading measure.
Relatively high heritabilities were observed for both reading ability and dyslexia indicating substantial genetic influences. Further, results indicated some overlap of genetic factors influencing reading ability and dyslexia.
Behavioral genetic studies offer a means of understanding the cause of dyslexia. This study extended research to a more diverse sample than extant studies and found lower heritability estimates of reading ability and dyslexia, but a similar pattern of results indicating possible genetic overlap. Twin studies provide perspective for discoveries of specific genes involved in dyslexia by quantifying the amount of variance waiting to be accounted for by genes while simultaneously providing an impetus to continue working on efforts for environmental intervention.
由于未能熟练阅读会带来诸多后果，阅读障碍成为了从业者、教育者和研究人员关注的焦点。本研究旨在简要概述双生子研究如何为包括阅读障碍在内的许多人类行为和障碍的原因提供深入了解，讨论行为遗传学研究结果的常见误解，简要回顾基因、环境与阅读障碍之间关系的证据，最后介绍一项关于阅读和阅读障碍的大型双胞胎研究的部分发现。
参与者为正在进行的阅读和阅读障碍纵向研究中一个大规模的、种族和社会经济背景多样化的双胞胎样本中的双胞胎。对 1024 名一年级双胞胎进行了标准化阅读测试，计算了阅读能力和阅读障碍的遗传力。如果孩子在阅读测试中得分低于第 15 百分位，则被认定为阅读障碍。
阅读能力和阅读障碍的遗传力均较高，表明存在大量遗传影响。此外，结果表明，影响阅读能力和阅读障碍的遗传因素存在一定程度的重叠。
行为遗传学研究为理解阅读障碍的原因提供了一种方法。本研究将研究扩展到比现有研究更具多样性的样本，发现阅读能力和阅读障碍的遗传力估计值较低，但结果模式相似，表明可能存在遗传重叠。双胞胎研究通过量化等待由基因解释的方差量，为发现阅读障碍相关特定基因提供了视角，同时也为继续努力进行环境干预提供了动力。
