Haplotype sharing tests of linkage disequilibrium in a Hutterite asthma data set

The Genetic Analysis Workshop 12 genome scan data set for "strict" asthma i n a Hutterite population was analyzed using haplotype sharing analysis (HSA ), which tests for differences in mean length of haplotype sharing around e ach marker for pairs of chromosomes in cases versus controls. The regions o f chromosome 1 and 8 where evidence for linkage was observed in published a nalyses were negative by HSA. HSA yielded positive results on chromosomes 7 , 12, 16, 18, and 21 (p = 0.003 on 21q). Although there are reports of supp ort for linkage to asthma in some of these regions, it is not known whether any represent true positives. Further study is needed of the possible role of length-based measures of linkage disequilibrium in recent population is olates. (C) 2001 Wiley-Liss, Inc.