Spina Bifida
Animal Science 434
Tuesday Lab
Ashley Driver
Emily Winther
Shauna Carter
Spina Bifida: What is it?
 Neural Tube Defect:
 When the neural tube fails to properly close
during the 4th week embryogenesis.
 One of the most common severely disabling
birth defects in the United States
 Approximately 1 in every 2,000 births is
affected.
 Currently there is no cure.
Spina Bifida: What is it?
 Three types of Spina Bifida
 Spina Bifida Occulta-Least Severe!
 Abnormal opening of spine-may have dimple on the skin,
tufts of hair, or nothing visible
 Commonly this isn’t even noticed
 Meningocele
 Protective coverings are pressed through openings in the
vertebrae and form a herniation
 Corrective surgery can be done
 Myelomeningocele-Most Severe!
 Vertebrae fail to fuse and the protective coverings, spinal
nerves, and spinal cord protrude
 The spinal cord fails to develop properly and nerves are
damaged
Development of spina bifida
in utero
Spina tissue is not present in
the sac in meningocele spina
bifida
Spina Bifida: A Closer Look
 Symptoms/Results:
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Paralysis of the legs
Incontinence of urine and feces
Anesthesia of the skin
Abnormalities of the hips, knees, and feet.
Hydrocephalus
 Build up of fluid on the skull or brain swelling
 Arnold-Chiari type II malformation
Cause
 Folic acid deficiencies from lack of intake
before and during pregnancy have shown
to be a cause
 The Folate Metabolism Pathway is
suspected to be a major contributor
 the most commonly studied thermolabile
mutation (C677T) in the MTHFR gene
 5,10-methylene tetrahydrofolate reductase
(MTHFR)
Cause
 Research has shown that people affected with
spina bifida have abnormal metabolism of folic acid
 This shows a possible link of an inborn defect
rather than a deficiency
 The discovery that periconceptional Folic Acid
supplementation has beneficial effects in terms of
reduction of 50–70% in the occurrence of NTD
 Antiepileptic Drug Valproic Acid (VPA) has been
shown to be associated with the cause
 Given to mice to study what levels cause the
defect
Relation to Domestic Animals
 Research involving lambs showed it to be
a autosomal recessive trait
 Mice are being used to study spina bifida
 Used to study in utero surgeries
 Spina Bifida has also been found in dogs
and cats
What’s Being Done?
 1996:
 The US FDA
authorized all
enriched grain
products be
fortified with FA.
 Optional start
March 1996,
required by 1998
Treatments
 Surgeries are being completed in utero to help
correct the problem
 This treatment helps preserve neurological function
 Surgery is the primary form of treatment with
many surgeries being performed shortly after
birth
 Folate supplementation helps prevent the defect
through amino acid synthesis and reducing
homocysteine levels
Surgery being performed to treat spina bifida in utero
References
 Northrup H, Volcik KA (2000) Spina bifida and other neural tube
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defects. Current Problems in Pediatrics (10):313-32.
Padmanabhan, Rengasamy (2006) Etiology, pathogenesis and
prevention of neural tube defects. Congenital
Anomalies 46 (2), 55-67.
www.cdc.gov/.../pubs/pubd/hestats/spine_anen.htm
http://facweb.bhc.edu/academics/science/lenertzk/biol145/NotBrai
n/SpinaBifida.htm
http://www.emedicinehealth.com/spina_bifida/page2_em.htm
http://jhered.oxfordjournals.org/cgi/content/abstract/75/5/378
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