Collins A, Morton N E
Human Genetics Group, University of Southampton, Princess Anne Hospital, UK.
Hum Hered. 1995 Nov-Dec;45(6):311-8. doi: 10.1159/000154299.
Sib pair tests for linkage to a quantitative trait or affection status are examined by simulation. A sibship of size s contributes only s-1 independent sib pairs but all s(s-1)/2 pairs are needed for an efficient test. Redundancy increases with sibship size. Using simulated data on the null hypothesis of no linkage, we have considered equal and unequal weights. Unequal weights lose power as measured by the equivalent number of observations, and goodness of fit to the theoretical distribution is degraded. The Fisher z(r) test with equally weighted pairs is more reliable than any t(r) test based on conjectured degrees of freedom, but significance levels must be established by simulation if the number of pairs is small or redundancy is large. An approach to parametric analysis through nuisance parameters is discussed.
通过模拟研究了用于定量性状或患病状态连锁分析的同胞对检验。大小为(s)的同胞组仅贡献(s - 1)个独立的同胞对，但为了进行高效检验，需要所有(s(s - 1)/2)对。冗余度随同胞组大小增加。利用无连锁零假设的模拟数据，我们考虑了等权重和不等权重。按等效观察数衡量，不等权重会降低检验效能，并且与理论分布的拟合优度会下降。具有等权重对的Fisher z(r)检验比基于推测自由度的任何t(r)检验更可靠，但如果对数较少或冗余度较大，则必须通过模拟来确定显著性水平。讨论了一种通过干扰参数进行参数分析的方法。
