Neurocristopathy: its growth and development in 20 years.

The neurocristopathies, originally defined in 1974 as a category of diseases arising in neural crest development are reviewed as to their current status. Accompanying the great advances in neural crest ontogeny, there has been an increase in the number and variety of neurocristopathies, particularly in the definition of craniofacial syndromes derived from the cranial crest mesectoderm. Molecular biology and genetics have added new dimensions in defining interrelationships between a number of entities. Environmental teratogens that cause neurocristopathies are also discussed. Neurocristopathy as a pathogenetic concept should continue to be useful as a structural framework for future investigations.