Epigenesis of Cerebral Asymmetry in Twins

描述（由申请人提供）：大脑不对称的生物学变异与语言功能的行为变异有关。确定对大脑不对称正态分布的相对环境和遗传贡献是确定促进或限制语言能力的特定因果因素的关键一步。通过对双胞胎进行研究，可以确定大脑不对称和语言能力的相关性是由遗传因素、环境因素还是这些影响的组合造成的。本研究将考察遗传、共享和独特的环境因素对大脑结构和功能不对称的影响。这些大脑不对称与口头和书面语言表现有关，包括：韦尼克区颞平面不对称、布罗卡区三角部不对称和小脑前叶不对称。中央沟不对称将作为一种非语言控制措施进行研究。还可以研究同卵双胞胎，以确定产生表型不一致的变量。初步观察表明，围产期危险因素影响双胞胎神经解剖学和行为相似性的程度。这项纵向研究还将确定大脑不对称是否会随着年龄的增长而改变，以及表型差异是否会随着年龄的增长而加剧或减弱。这项研究的结果将指导旨在阐明大脑不对称与语言能力之间的关系的研究，从遗传和/或环境的角度出发，可能确定围产期对大脑发育和行为的影响，将提供关于大脑不对称分子研究可行性的信息，并为临床医生、患者和家庭提供对认知能力生物学起源的更深入了解。

DESCRIPTION (provided by applicant): Biological variation in cerebral asymmetry is associated with behavioral variation in linguistic function. Identifying the relative environmental and genetic contributions to the normal distribution of cerebral asymmetry is a critical step in identifying specific causal factors that facilitate or limit verbal ability. Twins can be studied to determine whether the cerebral asymmetry and verbal ability correlation is attributable to genetic factors, environmental factors, or a combination of these influences. This study will examine the additive genetic, shared and unique environmental contributions to a structurally and functionally related set of brain asymmetries. These brain asymmetries have been associated with oral and written language performance and include: planum temporale asymmetry in Wernicke's area, pars triangularis asymmetry in Broca's area, and cerebellar anterior lobe asymmetry. Central sulcus asymmetry will be studied as a non-language control measure. Monozygotic twins can also be studied to identify variables that produce phenotypic discordance. Preliminary observations suggest that perinatal risk factors affect the degree of neuroanatomical and behavioral similarity in twins. This longitudinal study will also determine if cerebral asymmetry changes with age and whether phenotypic discordance is exaggerated or diminishes with age. Results from this study will guide research designed to elucidate the relation between cerebral asymmetry and verbal ability towards genetic and/or environmental sources, may identify perinatal influences on brain development and behavior, will provide information regarding feasibility of molecular studies of cerebral asymmetry, and provide clinicians, patients and families a greater understanding of the biological origins for cognitive ability.