Pedigrees of Belgian FTLD families DR25, DR26, DR27, DR28 and DR31, showing chromosome 17q21 haplotypes of selected relatives based on 14 STR markers; allele lengths are indicated in base pairs. The index patients (indicated with an arrowhead) were selected on the basis of allele sharing with the DR2–DR8 ancestral haplotype. The disease haplotype is boxed in black. The DR2–DR8 ancestral haplotype is highlighted in bold. Inferred haplotypes are shown between parentheses. For confidentiality reasons haplotypes are shown only for patients and obligate carriers; the number of at-risk individuals included in the genotyping is indicated within diamonds.