Neurocristopathy is a diverse class of pathologies that may arise from defects in the development of tissues containing cells commonly derived from the embryonic

neural crest The neural crest is a ridge-like structure that is formed transiently between the epidermal ectoderm and neural plate during vertebrate development. Neural crest cells originate from this structure through the epithelial-mesenchymal transition, ...

cell lineage. The term was coined by Robert P. Bolande in 1974. After the induction of the

, the newly formed neural crest cells (NCC) delaminate from their tissue of origin and migrate from the entire neural axis of the vertebrate embryo to specific locations where they will give rise to different cell derivatives. The formation of this cell population therefore requires a timely and spatially controlled interplay of inter- and intra-cellular signals. An alteration in the occurrence and timing of these signals leads to a set of syndromes called Neurocristopathies (NCP), which comprises a broad spectrum of congenital malformations affecting an appreciable percentage of newborns. Moreover, since NCC migrate along the embryo, they are susceptible to subtle changes in the environment both during their migration and upon arrival at their destination. This means that even little modifications, either genetically or environmentally caused, in the external cues that modulate NCC migration have a deep effect on the normal migration and differentiation of these cells, thus becoming a causative factor for the development of NCP. Recently, a new classification for this group of diseases has been proposed. This new criteria takes into account the axial origin of the NC population that contributes to the derived tissue affected in a particular NCP. According to this, some diseases have a single axial origin, i.e., they arise from an alteration in the development of only one NC population (e.g. cranial NCP, such as Auriculo Condylar Syndrome). However, other NCP arise from a defect in two or more NC populations (such as the CHARGE syndrome). Accepted examples of NCP are piebaldism,

Waardenburg syndrome Waardenburg syndrome is a group of rare genetic conditions characterised by at least some degree of congenital hearing loss and pigmentation deficiencies, which can include bright blue eyes (or Heterochromia iridum, one blue eye and one brown ey ...

, Hirschsprung disease, Ondine's curse (congenital central hypoventilation syndrome), pheochromocytoma,

paraganglioma A paraganglioma is a rare neuroendocrine tumour, neuroendocrine neoplasm that may develop at various body sites (including the head, neck, thorax and abdomen). When the same type of tumor is found in the adrenal gland, they are referred to as a p ...

Merkel cell carcinoma Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer occurring in about three people per million members of the population. It is also known as cutaneous APUDoma, Primary tumor, primary neuroendocrine tumor, neuroendocrine carcinoma ...

, multiple endocrine neoplasia, neurofibromatosis type I, CHARGE syndrome, familial dysautonomia, DiGeorge syndrome, Axenfeld-Rieger syndrome, Goldenhar syndrome (a.k.a.

hemifacial microsomia Hemifacial microsomia (HFM) is a congenital disorder that affects the development of the lower half of the face, most commonly the ears, the mouth and the mandible. It usually occurs on one side of the face, but both sides are sometimes affected. ...

), craniofrontonasal syndrome, congenital melanocytic nevus,

melanoma Melanoma is the most dangerous type of skin cancer; it develops from the melanin-producing cells known as melanocytes. It typically occurs in the skin, but may rarely occur in the mouth, intestines, or eye (uveal melanoma). In very rare case ...

, and certain

congenital heart defect A congenital heart defect (CHD), also known as a congenital heart anomaly, congenital cardiovascular malformation, and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. A congenital h ...

s of the outflow tract. Recently, many diseases have been incorporated as NCP, mainly based on the finding of new NC derivatives. In particular,

Multiple sclerosis Multiple sclerosis (MS) is an autoimmune disease resulting in damage to myelinthe insulating covers of nerve cellsin the brain and spinal cord. As a demyelinating disease, MS disrupts the nervous system's ability to Action potential, transmit ...

has been suggested as being neurocristopathic in origin. The usefulness of the definition resides in its ability to refer to a potentially common

etiological Etiology (; alternatively spelled aetiology or ætiology) is the study of causation or origination. The word is derived from the Greek word ''()'', meaning "giving a reason for" (). More completely, etiology is the study of the causes, origin ...

factor for certain neoplasms and/or congenital malformation associations that are otherwise difficult to group with other means of

nosology Nosology () is the branch of medical science that deals with the classification of diseases. Fully classifying a medical condition requires knowing its cause (and that there is only one cause), the effects it has on the body, the symptoms th ...

. Moreover, the classification of NCP is intended to help physicians understand the causal mechanism that drives the formation of a certain NCP, and therefore the selection of the correct diagnostic test and therapies.

References

{{reflist Animal developmental biology Medical terminology 1974 in biology Congenital disorders Genetic diseases and disorders Embryology of nervous system