Martinez M, Goldin L R
Clinical Neurogenetics Branch, National Institutes of Mental Health, Bethesda, MD.
Am J Hum Genet. 1991 Dec;49(6):1300-5.
We have compared the efficiency of the lod score test which assumes heterogeneity (lod2) to the standard lod score test which assumes homogeneity (lod1) when three-point linkage analysis is used in successive map intervals. If it is assumed that a gene located midway between two linked marker loci is responsible for a proportion of disease cases, then the lod1 test loses power relative to the lod2 test, as the proportion of linked families decreases, as the flanking markers are more closely linked, and as more map intervals are tested. Moreover, when multipoint analysis is used, linkage for a disease gene is more likely to be incorrectly excluded from a complete and dense linkage map if true genetic heterogeneity is ignored. We thus conclude that, in general, the lod2 linkage test is more efficient for detecting a true linkage when a complete genetic marker map is screened for a heterogeneous disorder.
我们比较了在连续图谱区间进行三点连锁分析时，假设存在基因异质性的对数优势比分检验（lod2）与假设基因同质性的标准对数优势比分检验（lod1）的效率。如果假定位于两个连锁标记位点中间的一个基因导致了一定比例的疾病病例，那么随着连锁家系比例的降低、侧翼标记连锁越紧密以及检测的图谱区间越多，lod1检验相对于lod2检验会失去效力。此外，当使用多点分析时，如果忽略了真正的遗传异质性，那么疾病基因的连锁在完整且密集的连锁图谱中更有可能被错误地排除。因此我们得出结论，一般来说，当针对一种异质性疾病筛查完整的遗传标记图谱时，lod2连锁检验在检测真正的连锁方面更有效。
