Figure 5.

Map of Finland showing birthplaces of ancestors of patients with HNPCC. The dotted line depicts the approximate border between old and new Finland. Each symbol depicts a kindred with several HNPCC patients. All of the kindreds share the same genomic deletion of exon 16 of the MLH1 gene. Based on linkage disequilibrium with numerous markers in and around the MLH1 gene, extensive haplotype conservation among kindreds marked in red suggests only a limited number of generations (perhaps 16) since founding. This finding is consistent with the population history of new Finland. In contrast, the two kindreds shown in blue share only a 2-cM core of the conserved haplotype with the other kindreds, suggesting a much older age of the mutation (perhaps 43 generations). This finding fits with their geographical location in old Finland. (Adapted from ref. 84.)