Genetic aspects of neurocutaneous disorders.

Among the conditions that are included under the heading of "neurocutaneous disorders" are neurofibromatosis 1, tuberous sclerosis complex, von Hippel-Lindau, incontinentia pigmenti, Sturge-Weber syndrome, hypomelanosis of Ito, and linear nevus sebaceous syndromes. The clinical features, pathogenesis, and neurobiological basis of some of these disorders are discussed in other articles in this issue. We will focus on genetic aspects of a selected subgroup of these conditions, concentrating on the genetic defect, mutation spectrum, clinical genetic testing, and issues pertinent to counseling.