Homozygosity mapping in 3p21. Regions of homozygosity shared by affected persons in 3p21. (Top) Regions exported directly from the Affymetrix Genotyping Console that are homozygous in the patients affected with GPS. A 5-Mb region is expanded below. The genotypes were exported from the Affymetrix Genotyping Console software Version 4.0 into an Excel file. The regions in yellow represent those SNPs where persons are homozygous; green, heterozygotes are heterozygous for the SNPs. The affected are homozygous for most of this 1.7-Mb region between 48.4 and 50.1 Mb. The majority of unaffected persons in families 1 and 2 are heterozygous for most of this region.