SIMULATION STUDY COMPARING INTERVAL ESTIMATES FOR THE RECOMBINATION FRACTION

Three interval estimation procedures were evaluated to determine the m ethod which provides the most accurate estimates for the recombination fraction, theta. The lod-0.83 support interval, the jackknife confide nce interval, and the confidence interval based on estimated asymptoti c standard error were compared by calculating the coverage probabiliti es of each. Family data that were simulated under the model of a singl e fully penetrant, dominant disease locus at some distance, theta, fro m fully informative matings were used. Comparisons were based on 1,000 random samples of size 20, 60, and 100 families. In addition, a metho dology for obtaining prediction intervals for theta was developed. Thi s procedure is of practical use and does not require asymptotic assump tions based on large sample theory. The results provide an a priori id ea about precision of the estimates, as well as empirical interval est imates of theta. Graphs of the authors' Monte Carlo intervals are pres ented for these simulations. Investigators studying different traits, however, could condition specifically on the family structure and dist ribution of the disease they are investigating and obtain similar grap hs. (C) 1995 Wiley-Liss, Inc.