Proposed minimum expansion of loss of heterozygosity (LOH) on chromosome 1. Relative positions of the studied microsatellite markers as well as of the RHD/RHCE and DARC gene loci are depicted. Chromosome 1 stretches apparently affected by LOH are represented by double arrows. This data compilation is based on results of microsatellite analysis of blood, erythropoietic blast-forming units (BFU-Es), and sorted blood cell subsets; for each patient, lines of evidence are specified below the arrows. In patient 5, LOH appeared to span the entire chromosome 1 (markers with an asterisk were analyzed only in patient 5).