Waxy keratoses of childhood in a segmental distribution.

Waxy keratoses of childhood is a rare genodermatosis previously noted in both familial and isolated presentations. Three previous cases have been described in which the lesions appeared over the trunk and extremities. We report a case in which the waxy keratoses of childhood lesions appeared in a segmental distribution along a single lower extremity, differing from the more extensive patterns reported previously. We suggest a possible postzygotic mutation hypothesis for this unique segmental distribution, addressing both the possibility of a genomic mosaicism and loss of heterozygosity.