Figure 2

Cosegregation of haplotypes at three chromosomal regions in family 70234. On top, the pedigree of this family is shown with circles denoting females and boxes males, with red filling denoting diagnosis of BC and shaded red also ovarian cancer. The pedigree is somewhat distorted in order to avoid recognition, but preserves the number of male and female meioses. Information about approximate age (in years) at diagnosis of cancer is shown below symbols (Br for breast and Ov for ovarian). One woman inherited a 999del5 BRCA2 mutation from her father (red box), not otherwise blood-related to this family. This woman and one other (denoted by not GWS) were not included in the genome-wide search. One of a pair of identical twins was omitted in linkage calculations. Under the pedigree, genotypes of markers of interest are shown (with chromosomal band position, marker names and genomic distance shown at the left, brackets indicating position between sites of relevant recombination). Colouring of alleles denotes whether they belong to a shared haplotype (allele frequency shown in the rightmost column) or derive from a recombined chromosome (blue). Plain (not coloured) alleles denoted 11 and 3 at D2S367 and D2S2163 respectively, are identical by state, but probably not by descent, to the commonly segregated allele (conclusion supported by fine-genotyping of additional markers, data not shown). The low frequency (0.06) of the shared D6S434 allele was validated by typing in 59 unrelated Icelandic control individuals. This figure was 0.02 in the controls (2/118), which coincides with the published Genethon frequency of the allele.