ON ESTIMATION OF LINKAGE TEST POWER

Two methods of estimating linkage test power are proposed. The first m ethod is based on the maximum likelihood (ML) estimate of the recombin ation fraction and is intended for use with a likelihood ratio test (L RT) in the form of a chi(2) or lod score. The power is estimated throu gh a noncentral chi(2) distribution with a specially chosen noncentral ity parameter. The second method uses the LRT constructed for a simple alternative hypothesis regarding the recombination fraction value. Th e approximate distribution of this test and a method of estimating its power is proposed. Using simulated pedigree data, the power estimates for these two methods were shown to be satisfactory. Comparisons amon g these two methods and the computer simulation approach of Boehnke [1 986] are performed. (C) 1996 Wiley-Liss, Inc.