Inheritance of the p16-Leiden allele in families 1 and 4 from a common ancestor in the late eighteenth century. Melanoma cases are shown in black. The bar underneath the family members depicts the seven-marker founder haplotype dispersed over ∼20 cM. The marker that migrates with p16-Leiden is indicated in black, and the markers that have lost the founder allele owing to recombinations in the families and in the population are depicted in white. All numbered members have been haplotyped, although only the p16-Leiden-related haplotypes are visualized. Melanoma-free carriers of the p16-Leiden allele are indicated by a black dot, whereas melanoma patient 1.20, who is no carrier of the p16-Leiden allele, is depicted by a white dot.
