In the first family, linkage was found to chromosome 17 markers flanking the keratin 14 gene (D17S74: Zmax = +2.45, theta = 0.10; COL1A1: Zmax = +0.97, theta = 0.00) and markers near the keratin 5 gene on chromosome 12 were excluded (D12S17: Z less than -2.0, theta = 0.08; COL2A1: Z less than -2.0, theta = 0.13). In contrast, the second family showed linkage to the region containing the keratin 5 gene (D12S17: Zmax = +1.37, theta = 0.08; COL2A1: Zmax = +0.33, theta = 0.15) and was not linked to the keratin 14 gene (D17S74: Z less than -2.0, theta = 0.14).