Spina BifidaSpina Bifida

Animal Science 434Animal Science 434Tuesday LabTuesday LabAshley DriverAshley DriverEmily WintherEmily WintherShauna CarterShauna Carter

Spina Bifida: What is it?Spina Bifida: What is it?

Neural Tube Defect:Neural Tube Defect: When the neural tube fails to properly close When the neural tube fails to properly close

during the 4during the 4thth week embryogenesis. week embryogenesis. One of the most common severely disabling One of the most common severely disabling

birth defects in the United Statesbirth defects in the United States Approximately 1 in every 2,000 births is Approximately 1 in every 2,000 births is

affected.affected. Currently there is no cure.Currently there is no cure.

Spina Bifida: What is it?Spina Bifida: What is it?

Three types of Spina BifidaThree types of Spina Bifida Spina Bifida Occulta-Least Severe!Spina Bifida Occulta-Least Severe!

Abnormal opening of spine-may have dimple on the skin, Abnormal opening of spine-may have dimple on the skin, tufts of hair, or nothing visibletufts of hair, or nothing visible

Commonly this isn’t even noticedCommonly this isn’t even noticed MeningoceleMeningocele

Protective coverings are pressed through openings in the Protective coverings are pressed through openings in the vertebrae and form a herniationvertebrae and form a herniation

Corrective surgery can be doneCorrective surgery can be done Myelomeningocele-Most Severe!Myelomeningocele-Most Severe!

Vertebrae fail to fuse and the protective coverings, spinal Vertebrae fail to fuse and the protective coverings, spinal nerves, and spinal cord protrudenerves, and spinal cord protrude

The spinal cord fails to develop properly and nerves are The spinal cord fails to develop properly and nerves are damaged damaged

Spina tissue is not present in the sac in meningocele spina bifida

Development of spina bifida in utero

Spina Bifida: A Closer LookSpina Bifida: A Closer Look

Symptoms/Results:Symptoms/Results: Paralysis of the legsParalysis of the legs Incontinence of urine and fecesIncontinence of urine and feces Anesthesia of the skinAnesthesia of the skin Abnormalities of the hips, knees, and feet.Abnormalities of the hips, knees, and feet. HydrocephalusHydrocephalus

Build up of fluid on the skull or brain swellingBuild up of fluid on the skull or brain swelling

Arnold-Chiari type II malformation Arnold-Chiari type II malformation

CauseCause

Folic acid deficiencies from lack of intake Folic acid deficiencies from lack of intake before and during pregnancy have shown before and during pregnancy have shown to be a causeto be a cause

The Folate Metabolism Pathway is The Folate Metabolism Pathway is suspected to be a major contributorsuspected to be a major contributor the most commonly studied thermolabile the most commonly studied thermolabile

mutation (C677T) in the MTHFR genemutation (C677T) in the MTHFR gene 5,10-methylene tetrahydrofolate reductase 5,10-methylene tetrahydrofolate reductase

(MTHFR)(MTHFR)

CauseCause Research has shown that people affected with Research has shown that people affected with

spina bifida have abnormal metabolism of folic acidspina bifida have abnormal metabolism of folic acid This shows a possible link of an inborn defect This shows a possible link of an inborn defect

rather than a deficiencyrather than a deficiency The discovery that periconceptional Folic Acid The discovery that periconceptional Folic Acid

supplementation has beneficial effects in terms of supplementation has beneficial effects in terms of reduction of 50–70% in the occurrence of NTD reduction of 50–70% in the occurrence of NTD

Antiepileptic Drug Valproic Acid (VPA) has been Antiepileptic Drug Valproic Acid (VPA) has been shown to be associated with the causeshown to be associated with the cause Given to mice to study what levels cause the Given to mice to study what levels cause the

defectdefect

Relation to Domestic AnimalsRelation to Domestic Animals

Research involving lambs showed it to be Research involving lambs showed it to be a autosomal recessive traita autosomal recessive trait

Mice are being used to study spina bifidaMice are being used to study spina bifida Used to study in utero surgeriesUsed to study in utero surgeries

Spina Bifida has also been found in dogs Spina Bifida has also been found in dogs and catsand cats

What’s Being Done?What’s Being Done? 1996:1996:

The US FDA The US FDA authorized all authorized all enriched grain enriched grain products be products be fortified with FA.fortified with FA.

Optional start Optional start March 1996, March 1996, required by 1998required by 1998

TreatmentsTreatments

Surgeries are being completed in utero to help Surgeries are being completed in utero to help correct the problemcorrect the problem This treatment helps preserve neurological functionThis treatment helps preserve neurological function

Surgery is the primary form of treatment with Surgery is the primary form of treatment with many surgeries being performed shortly after many surgeries being performed shortly after birthbirth

Folate supplementation helps prevent the defect Folate supplementation helps prevent the defect through amino acid synthesis and reducing through amino acid synthesis and reducing homocysteine levelshomocysteine levels

Surgery being performed to treat spina bifida in utero

ReferencesReferences

Northrup H, Volcik KANorthrup H, Volcik KA (2000) Spina bifida and other neural tube (2000) Spina bifida and other neural tube defects. defects. Current Problems in Pediatrics (10):313-32.Current Problems in Pediatrics (10):313-32.

Padmanabhan, Rengasamy (2006) Padmanabhan, Rengasamy (2006) Etiology, pathogenesis and Etiology, pathogenesis and prevention of neural tube defects. Cprevention of neural tube defects. Congenital ongenital AnomaliesAnomalies 46 (2), 55-67. 46 (2), 55-67.

www.cdc.govwww.cdc.gov/.../pubs/pubd/hestats/spine_anen.htm/.../pubs/pubd/hestats/spine_anen.htm http://facweb.bhc.edu/academics/science/lenertzk/biol145/NotBraihttp://facweb.bhc.edu/academics/science/lenertzk/biol145/NotBrai

n/SpinaBifida.htmn/SpinaBifida.htm http://www.emedicinehealth.com/spina_bifida/page2_em.htmhttp://www.emedicinehealth.com/spina_bifida/page2_em.htm http://jhered.oxfordjournals.org/cgi/content/abstract/75/5/378http://jhered.oxfordjournals.org/cgi/content/abstract/75/5/378 Images from google.comImages from google.com