Spina Bifida

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Spina Bifida

• Animal Science 434
• Tuesday Lab
• Ashley Driver
• Emily Winther
• Shauna Carter

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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.

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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 isnt 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

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Development of spina bifida in utero
Spina tissue is not present in the sac in
meningocele spina bifida
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Spina Bifida A Closer Look

• Symptoms/Results
• 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

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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)

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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 5070 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

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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

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Whats Being Done?

• 1996
• The US FDA authorized all enriched grain products
  be fortified with FA.
• Optional start March 1996, required by 1998

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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

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Surgery being performed to treat spina bifida in
utero
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References

• Northrup H, Volcik KA (2000) Spina bifida and
  other neural tube 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/b
  iol145/NotBrain/SpinaBifida.htm
• http//www.emedicinehealth.com/spina_bifida/page2_
  em.htm
• http//jhered.oxfordjournals.org/cgi/content/abstr
  act/75/5/378
• Images from google.com