Sarnat Harvey B, Flores-Sarnat Laura
Departments of Clinical Neurosciences and Paediatrics, Division of Paediatric Neurology, University of Calgary, Alberta Children's Hospital, Calgary, Canada.
Handb Clin Neurol. 2013;111:309-14. doi: 10.1016/B978-0-444-52891-9.00036-1.
Neural crest progenitor cells are identified at the lateral margins of the neural placode at the time of gastrulation. With folding of the placode, these precursors are brought to the dorsal midline of the neural tube at the site of closure, become committed to neural crest lineage and almost immediately migrate peripherally to various predetermined sites in the body and then differentiate as a variety of cellular types in all three of the traditional "germ layers." All of these processes of migration and differentiation of neural crest are precisely genetically programed, temporally and spatially, by a variety of genes. Primary neurocutaneous syndromes are all very different diseases with different genetic mutations, but the unifying factor amongst them is that all are neurocristopathies and can be explained as such, including the tumor-suppressor function of several of these genes, especially those of neurofibromatosis 1 and 2 and tuberous sclerosis. This chapter reviews the principal genes that program neural crest development and also are documented, implicated, or suspected in the pathogenesis of neurocutaneous syndromes. Recent genetic discoveries are noted in epidermal nevus syndrome, including Proteus syndrome and their association with hemimegalencephaly and congenital infiltrating lipomatosis of the face.
神经嵴祖细胞在原肠胚形成时于神经板的外侧边缘被识别出来。随着神经板的折叠，这些前体细胞在神经管闭合处被带到神经管的背中线，确定为神经嵴谱系，几乎立即向身体外周的各个预定部位迁移，然后在所有三个传统的“胚层”中分化为多种细胞类型。神经嵴的所有这些迁移和分化过程在时间和空间上都由多种基因精确地进行遗传编程。原发性神经皮肤综合征都是具有不同基因突变的非常不同的疾病，但它们之间的统一因素是所有这些都是神经嵴病，可以这样解释，包括其中一些基因的肿瘤抑制功能，特别是神经纤维瘤病1型和2型以及结节性硬化症的那些基因。本章回顾了编程神经嵴发育且在神经皮肤综合征的发病机制中有记录、涉及或疑似相关的主要基因。表皮痣综合征的近期遗传学发现也被提及，包括变形综合征及其与半侧巨脑畸形和面部先天性浸润性脂肪瘤病的关联。
