Knapp M
Institute for Medical Statistics, University of Bonn, Germany.
Ann Hum Genet. 1998 Jan;62(Pt 1):75-87. doi: 10.1046/j.1469-1809.1998.6210075.x.
Risch and Zhang recently proposed to use extreme discordant sib pairs for mapping quantitative trait loci. Here, it is shown that the set of genetically possible distributions of the number of marker alleles in such sib-pairs is described by two inequalities. Thus, a likelihood ratio test analogous to Holmans's possible triangle test for affected sib pairs can be defined. The performance of this test is compared to the mean test considered by Risch and Zhang. For most of the genetic models considered, the mean test is slightly more powerful than the restricted likelihood ratio test. However, for models with a rare recessive gene (or equivalently a common dominant gene), the restricted likelihood ratio test is much more powerful.
里施和张最近提议使用极端不一致的同胞对来定位数量性状基因座。在此表明，此类同胞对中标记等位基因数量的遗传可能分布集由两个不等式描述。因此，可以定义一种类似于霍尔曼斯针对患病同胞对的可能三角形检验的似然比检验。将此检验的性能与里施和张所考虑的均值检验进行比较。对于所考虑的大多数遗传模型，均值检验比受限似然比检验的功效略强。然而，对于具有罕见隐性基因（或等效的常见显性基因）的模型，受限似然比检验的功效要强得多。
