Participants enrolled in the Registry by contacting the registry officials. All participants participated in a phone interview with the study research nurse. Participants were asked about diagnostic testing, treatments, birth history, medical history, degree and type of involvement, current physical condition, and other family members with skin disorders. A quality of life index was embedded in the interview. Participants also indicated whether they would like to be contacted about participating in clinical research. This information was complemented by an enrollment form from the enrollee's caregiver.