Editor—Port wine stains (PWS) are common capillary vascular malformations of the dermis, which are present at birth and grow with the person. PWS most commonly affect the head, face, and upper body.1 Although usually considered to be sporadic lesions, a survey of patients attending for laser treatment of PWS has shown a higher than expected prevalence of lesions in relatives, suggesting a hereditary predisposition to these malformations.2

Families have previously been reported with autosomal dominant inheritance of capillary vascular malformations. In these families, the lesions can be atypical in distribution, with affected subjects having multiple lesions on the trunk and limbs, as well as on the face3-5 (J Clayton-Smith, 1998, personal communication). In other families, the common median telangiectatic naevus or “stork mark” has been shown to segregate as an autosomal dominant trait.6

In this report, we present a family with four subjects affected with classical single PWS. The family pedigree is shown in fig 1, with clinical photographs of the affected subjects in fig 2. I.1 and I.2 were not available to be examined, but neither was reported to have a port wine stain.