01325nas a2200205   4500000000100000008004100001260001200042653001200054653002700066653001900093653001100112653001200123653001600135100001200151245005400163300001100217490000700228520087000235022001401105       1986                            d  c1986 0710aAlleles10aDisease Susceptibility10aHLA-D Antigens10aHumans10aleprosy10aProbability1 aLange K00aA test statistic for the affected-sib-set method.  a283-900 v503 a<p>This paper discusses generalizations of the affected-sib-pair method. First, the requirement that sib identity-by-descent relations be known unambiguously is relaxed by substituting sib identity-by-state relations. This permits affected sibs to be used even when their parents are unavailable for typing. In the limit of an infinite number of marker alleles each of infinitesimal population frequency, the identity-by-state relations coincide with the usual identity-by-descent relations. Second, a weighted pairs test statistic is proposed that covers affected sib sets of size greater than two. These generalizations make the affected-sib-pair method a more powerful technique for detecting departures from independent segregation of disease and marker phenotypes. A sample calculation suggests such a departure for tuberculoid leprosy and the HLA D locus.</p>  a0003-4800