Spina Bifida Research Resource Pursues Insight Into Birth Defect

The causes of the most common permanently disabling birth defect in the United States, spina bifida, are not well understood. And, there is no cure.

The most recent studies indicate that in the United States, approximately 13 percent of individuals born with spina bifida die before their first birthday; 25 percent die before turning age 18. Persons with this condition also are subject to excess mortality throughout adulthood.

The good news is, thanks to the latest medical treatments and technology, most people with spina bifida live a normal life. They have careers, get married and have children.

Nonetheless, preventing spina bifida is the ultimate goal. And, that goal is the driving force for several researchers at the Texas A&M Health Science Center Institute of Biosciences and Technology at Houston.

"My research focuses on identifying genes that influence the risk of common birth defects in humans and determining how such genes interact with each other and with environmental factors to ultimately result in these conditions," said Laura Mitchell, Ph.D. "Most of my research focuses on three groups of birth defects: neural tube defects - which include anencephaly and spina bifida - congenital heart defects and facial clefts - which include cleft lip and cleft palate."

Dr. Mitchell is principal investigator for the Spina Bifida Research Resource (SBRR) at the HSC-Institute of Biosciences and Technology and a member of its Center for Environmental and Genetic Medicine.

The Spina Bifida Association of America reports about 70,000 people in the United States have spina bifida. This condition occurs in the first month of pregnancy, when the neural tube, the structure that develops into the spinal cord and brain, does not form properly.

Although a woman can reduce her risk of having a child with spina bifida or other types of neural tube defects by taking a multivitamin containing folic acid prior to and during pregnancy, approximately 3,000 pregnancies are affected by spina bifida each year in the United States.

"Individuals with spina bifida are at risk for lower extremity weakness and paralysis, sensory loss, bowel and bladder dysfunction, orthopedic abnormalities, associated malformations of the nervous system, and specific learning disabilities," Dr. Mitchell said. "These individuals require life-long, specialized, multi-disciplinary health care."

Dr. Mitchell and her SBRR colleagues at HSC-IBT and the University of Pennsylvania School of Medicine are analyzing data provided by more than 600 spina bifida families nationwide since the study opened in 1997. Funded for the last five years by two grants from the National Institutes of Health, their work focuses on genes that may influence development of spina bifida.

"We have conducted analyses of about a half-dozen genes and had some positive findings," Dr. Mitchell said. "The study will continue for an additional five years with funds from a new NIH grant. This will allow us to recruit an additional 400 families and expand the number of genes that can be studied."