Definition: Spina bifida (SB) is one of the neural tube defects (NTDs) caused by the failure of the fetus’s spine to close properly during the first month of pregnancy.
The most common types of SB are:
spina bifida occulta (one or more vertebrae are malformed and covered by a layer of skin)
meningocele (the spinal cord develops normally but the meninges protrude from a spinal opening)
myelomeningocele (the spinal cord and the meninges protrude from an opening in the spine)
spina bifida aperta
spina bifida cystica
Localization
cervical spina bifida
thoracic spina bifida
lombar spina bifida
sacral spina bifida
Suceptibility
variation in genes that are involved in the folate-homocysteine metabolic pathway
- variants in gene coding for methylenetetrahydrofolate reductase (MTHFR)
- variants in gene coding for the trifunctional enzyme methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase/formyltetrahydrofolate synthetase (MTHFD1) (12384833)
- variants in genes involved in homocysteine remethylation/methionine biosynthesis
- methionine synthase (MTR)
- methionine synthase reductase (MTRR)
Loci
- 1q43
- 5p15.3-p15.2
X-linked spina bifida (MIM.300293)
- lumbosacral spina bifida and myeloschisis
- de novo/autosomal translocation, t(X;22)(q27;q12.1)
Associations
encephalocele (9182784)
anencephaly (anencephaly-spina bifida association)
- X-linked anencephaly-spina bifida association (MIM.301410)
sacral agenesis
neural crest anomalies (8.5%) (10508971)
- auditory
- pigmentary disorders
- familial neural crest anomalies (3.9%)
- Waardenburg syndrome (1.7%) (PAX3 mutations) (8209923, 8465867)
association split hand-onbstructive uropathy- spina bifida and diaphragmatic defects (MIM.183802) (3308683)
abdominal wall defects
-
gastroschisis
- spina bifida-gastroschisis association (hp7883)
-
omphalocele
- association gonadal agenesis, encephalocele, spina bifida, omphalocele (GAESBO) (9182784)
hypospadias (7977461)
multiple pilomatricomas (15804314)
Etiological forms
non-syndromal spina bifida
- non-syndromal sporadic spina bifida
- non-syndromal familial spina bifida
syndromal spina bifida
- Waardenburg syndrome type 1 (WS1)
- trisomy 13
- trisomy 18
- various chromosome rearrangements
See also
spinal malformations
neural tube defects
myelomeningocele
References
De Marco P, Merello E, Mascelli S, Capra V. Current perspectives on the genetic causes of neural tube defects. Neurogenetics. 2006 Nov;7(4):201-21. PMID: 16941185