title: Classification, clinical features, and genetics of neural tube defects.
abstract: Neural tube defects (NTDs) constitute a major health burden (0.5-2/1000 pregnancies worldwide), and remain a preventable cause of still birth, neonatal, and infant death, or significant lifelong handicaps. The malformations result from failure of the neural folds to fuse in the midline, and form the neural tube between the third and the fourth week of embryonic development. This review article discusses their classification, clinical features, and genetics. Most NTDs are sporadic and both genetic, and non-genetic environmental factors are involved in its etiology. Consanguinity was suggested to contribute to the high incidence of NTDs in several countries, including Saudi Arabia. Syndromes, often associated with chromosomal anomalies, account for <10% of all NTDs; but a higher proportion (20%) has been documented in Saudi Arabia. Genetic predisposition constitutes the major underlying risk factor, with a strong implication of genes that regulate folate one-carbon metabolism and planar cell polarity.
authors.affiliation: Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, PO Box 2925, Riyadh 11461, Kingdom of Saudi Arabia. E-mail: mustafa_salih05@yahoo.com.
authors.forename: Mustafa A
authors.initials: MA
authors.lastname: Salih
authors.forename: Waleed R
authors.initials: WR
authors.lastname: Murshid
authors.forename: Mohammed Z
authors.initials: MZ
authors.lastname: Seidahmed
mesh_terms: D003241:Consanguinity; D006801:Humans; D007231:Infant, Newborn; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D009436:Neural Tube Defects / Q000145:classification / Q000175:diagnosis / Q000235:genetics
chemical_list: D042965:Methylenetetrahydrofolate Reductase (NADPH2)