Programa de Pós-Graduação em Ciências Médicas, Universidade de Brasília, Brasília, DF, Brazil.
Dement Geriatr Cogn Disord. 2012;33(5):311-7. doi: 10.1159/000339672. Epub 2012 Jul 2.
Alzheimer's disease (AD) is the most common form of dementia worldwide, and bears remarkable evidence for a differential prevalence among continental populations. In this scenario, estimating ancestry proportions in recently admixed populations is a strategy that can help increasing knowledge about the genetic structure of this complex trait.
AIM/METHODS: Our purpose was to assess mean ancestry estimates for the three main parental contributors to the Brazilian contingent (European, African and Amerindian) using a panel of 12 ancestry informative markers. Outpatients with the late-onset form of AD (n = 120) were compared for ancestry levels with non-cognitively impaired subjects (n = 412) in the Midwest Brazil, controlling for classic clinical, social and anthropometric risk factors.
Our findings show a 3-fold greater genetic Amerindian content among control subjects compared to AD patients (p < 0.001).
Our results suggest that the allelic architecture of Native Americans can confer protection against the onset of the disease.
阿尔茨海默病（AD）是全世界最常见的痴呆症形式，并且在大陆人群中具有显著的差异流行证据。在这种情况下，估计最近混合人群中的祖先比例是一种可以帮助增加对这种复杂特征遗传结构的了解的策略。
目的/方法：我们的目的是使用一组 12 个祖先信息标记来评估巴西人群的三个主要父母贡献者（欧洲人、非洲人和美洲印第安人）的平均祖先估计值。我们将巴西中西部的晚发性 AD 患者（n=120）与认知功能正常的对照组（n=412）进行比较，控制经典的临床、社会和人体测量风险因素。
我们的研究结果显示，与 AD 患者相比，对照组的遗传美洲印第安人成分高出 3 倍（p<0.001）。
我们的结果表明，美洲原住民的等位基因结构可以提供对疾病发病的保护。
