The importance of connections: Joining components of the Hutterite pedigree

We analyzed a quantitative trait (serum IgE levels), and a binary trait (as thma), in four Hutterite sub-pedigrees. A genome screen for asthma was perf ormed using GENEHUNTER, and interesting regions were followed up using exte nded pedigrees and the FASTLINK package. Markov chain Monte Carlo (MCMC) me thods were used to assess haplotype sharing among affected individuals (MOR GAN/AUTOZYG), and to perform a combined oligogenic segregation and linkage analysis (LOKI) for log(10)(IgE). We found evidence for at least two suscep tibility loci for asthma on chromosome 5, and a QTL for log(10)(IgE) on chr omosome 1. Our analyses demonstrate that using the most complete pedigree s tructure possible is advisable, with attention to the possibility of hetero geneity among subunits of a very large pedigree, (C) 2001 Wiley-Liss, Inc.