Failure of migration of neural crest cells is seen in
**Core Concept**
The neural crest is a critical embryonic structure that gives rise to various cell types, including neurons, glial cells, and pigment cells. The migration of neural crest cells is essential for the proper development of the nervous system and other associated structures.
**Why the Correct Answer is Right**
The failure of migration of neural crest cells is associated with neurocristopathies, a group of congenital disorders. One such condition is Hirschsprung's disease, where the absence of neural crest-derived enteric neurons leads to a functional obstruction of the colon. The enteric nervous system, derived from neural crest cells, is responsible for regulating gut motility. In Hirschsprung's disease, the aganglionic segment of the colon lacks these neurons, resulting in a failure of peristalsis and a buildup of feces.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not directly related to the migration of neural crest cells. While it may be a congenital disorder, it is not specifically related to neural crest development.
* **Option B:** This option is incorrect as it is a condition related to the development of the neural tube, not neural crest cells.
* **Option C:** This option is incorrect as it is a condition related to the development of the brain, not neural crest cells.
**Clinical Pearl / High-Yield Fact**
The neural crest gives rise to a wide range of cell types, including neurons, glial cells, and pigment cells. Failure of neural crest migration can lead to a variety of congenital disorders, including Hirschsprung's disease, Waardenburg syndrome, and neurofibromatosis.
**Correct Answer:** D.