Test S of Haplotype Concordance and Discordance

The test presented here is based upon the proband and his/her affected as well as unaffected siblings. Here, the siblings are analyzed in terms of similarities of haplotypes. The proposed ‘S’ test is used in testing hypothesis that a particular disease has random pattern of inheritance against the alternative hypothesis that it has non-random pattern of inheritance. Probability distribution, mean and variance of the test are derived under the null hypothesis of random inheritance of the disease. It is then applied to data set of varying size of sibships having at least one affected and one unaffected sibs to investigate the existence of linkage disequilibrium.