The detection of linkage disequilibrium in molecular sequence data.
The detection of linkage disequilibrium in molecular sequence data.
复制标题
分子序列数据中连锁不平衡的检测。
DOI：
10.1093/genetics/140.1.377
复制
发表时间：
1995
期刊：
影响因子：
3.3
通讯作者：
Lewontin,RC
中科院分区：
文献类型：
--
作者：
Lewontin,RC
在序列水平上对自然群体遗传变异的研究通常表明，大多数多态位点的等位基因频率是非常不对称的，在固定位点附近的等位基因更罕见。当一个位点上的稀有等位基因在样本中只出现几次时，比如说少于5个代表，就很难从关联检验中检测出位点之间的连锁不平衡。这是一个后果的数字属性，即使是最强大的测试的关联，费舍尔的确切测试。样本中少于5个代表的位点应排除在关联检验之外，但这通常会使很少的位点对符合检验条件。一个测试的整体连锁不平衡，根据所观察到的连锁不平衡的迹象，推导出可以使用所有的数据。它表明，更多的权力，可以通过增加确定的序列的长度比通过增加相同的总工作的基因组采样的数量来实现。
Studies of genetic variation in natural populations at the sequence level usually show that most polymorphic sites are very asymmetrical in allele frequencies, with the rarer allele at a site near fixation. When the rarer allele at a site is present only a few times in the sample, say below five representatives, it becomes very difficult to detect linkage disequilibrium between sites from tests of association. This is a consequence of the numerical properties of even the most powerful test of association, Fisher's exact test. Sites with fewer than five representatives in the sample should be excluded from association tests, but this generally leaves few site pairs eligible for testing. A test for overall linkage disequilibrium, based on the sign of the observed linkage disequilibria, is derived which can use all the data. It is shown that more power can be achieved by increasing the length of sequence determined than by increasing the number of genomes sampled for the same total work.