Neural tube defects are common congenital abnormalities of the central nervous system.Expression or mutation of many types of genes have been found to exhibit an especially correlation with the neurulation and neural tube defects.They are: (1)development regulation genes and transcription factors genes, (2)oncogenes and tumor supressor genes, (3)growth factors genes and their receptors genes, (4)protein kinase C related genes, (5)homocysteine metabolism related genes, (6)and others, such as cytoskeleton and cell junction genes.