Search

Temporal lobe epilepsy (TLE), traditionally thought to develop largely due to environmental factors, has recently become the focus of association studies in an effort to determine genetic risk factors. Here we examine all previous claims of association of genetic polymorphisms with TLE by attempting replication in a cohort of 339 TLE patients of European origin. We also examine if these variants contribute to other types of epilepsy by examination in a larger cohort of 752 patients representing a range of different epilepsies. We fail to clearly replicate any of the previously reported associations and also fail to show a role for these variants in the development of other forms of epilepsy. Although our results cannot definitively rule out a role for these genes, they do suggest that most and perhaps all of the previous associations are false positives. As has been the experience with other diseases, these results highlight the importance of larger sample sizes and replication. In TLE, it appears that collaboration before publication is the best option to increase sample size sufficiently in the short term. These general principles are applicable to other studies undertaken for common complex diseases., Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

The current genetic makeup of Latin America has been shaped by a history of extensive admixture between Africans, Europeans and Native Americans, a process taking place within the context of extensive geographic and social stratification. We estimated individual ancestry proportions in a sample of 7,342 subjects ascertained in five countries (Brazil, Chile, Colombia, México and Perú). These individuals were also characterized for a range of physical appearance traits and for self-perception of ancestry. The geographic distribution of admixture proportions in this sample reveals extensive population structure, illustrating the continuing impact of demographic history on the genetic diversity of Latin America. Significant ancestry effects were detected for most phenotypes studied. However, ancestry generally explains only a modest proportion of total phenotypic variation. Genetically estimated and self-perceived ancestry correlate significantly, but certain physical attributes have a strong impact on self-perception and bias self-perception of ancestry relative to genetically estimated ancestry.

The current genetic makeup of Latin America has been shaped by a history of extensive admixture between Africans, Europeans and Native Americans, a process taking place within the context of extensive geographic and social stratification. We estimated individual ancestry proportions in a sample of 7,342 subjects ascertained in five countries (Brazil, Chile, Colombia, México and Perú). These individuals were also characterized for a range of physical appearance traits and for self-perception of ancestry. The geographic distribution of admixture proportions in this sample reveals extensive population structure, illustrating the continuing impact of demographic history on the genetic diversity of Latin America. Significant ancestry effects were detected for most phenotypes studied. However, ancestry generally explains only a modest proportion of total phenotypic variation. Genetically estimated and self-perceived ancestry correlate significantly, but certain physical attributes have a strong impact on self-perception and bias self-perception of ancestry relative to genetically estimated ancestry.