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 4 th 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

Spina tissue is not present in the sac in meningocele spina bifida Development of spina bifida in utero

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

Cause 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 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 defects. Current Problems in Pediatrics (10):  Padmanabhan, Rengasamy (2006) Etiology, pathogenesis and prevention of neural tube defects. Congenital Anomalies 46 (2),   n/SpinaBifida.htm n/SpinaBifida.htm n/SpinaBifida.htm    Images from google.com