Northwestern Programs Aims At Revealing Genetic Causes Of Spina Bifida

Johnny was born with spina bifida, a common birth defect that deforms the spinal cord and which researchers believe may be linked to mutations in certain genes. Spina bifida affects about four of every 1,000 children born.

To assist in the search for these aberrant genes, Johnny and his parents and families like them contributed DNA samples to the Spina Bifida Genetic Research Project at Northwestern.

Program researchers are analyzing DNA samples from the Does and other families whose children have spina bifida to determine which genetic traits are found more often in these families and how these genes interact with each other and the environment. They also are conducting experiments to identify genes that may increase risk for spina bifida.

Jeffrey S. Nye, M.D., directs the program and is principal investigator on three National Institutes of Health-sponsored studies to determine the genetic basis of spina bifida. Nye, who also has a Ph.D., is an assistant professor of molecular pharmacology and biological chemistry and of pediatrics at the Medical School and at Children’s Memorial Hospital.

Numerous studies have implicated certain drugs, nutritional status (such as folic acid deficiency) and genetic factors in the development of spina bifida, yet scientists are still uncertain as to its actual cause.

Nye, with Northwestern co-investigators David G. McLone, M.D., Joel Charrow, M.D., John F. Sarwark, M.D., and Marcy Speer, Duke University, identified a number of common traits among families who have a child with spina bifida, such as deafness, areas of the hair and skin that lack pigmentation, early graying of the hair and deformities of the face and hands.

"For decades, researchers have known about the increased risk to families for having a second or third child with spina bifida. However, genetic factors that predispose to spina bifida have still not been identified," Nye said.

"Identifying these risk factors will give prospective parents the power to predict their likelihood of having a child with this devastating condition," he said.

Spina bifida occurs during fetal development and results from improper closure of the neural tube, the embryonic structure from which the brain and spinal cord are formed. In the severe forms of spina bifida, part of the spinal cord is left uncovered by the skin and bone or actually protrudes from the spinal column. More severe forms of neural tube defect are often fatal for the developing fetus or newborn.

Children with spina bifida usually have limited or absent bladder and bowel functions and frequently have paralyzed legs. Fortunately, the lethal complications of spina bifida, such as infection and hydrocephalus or build-up of pressured fluid in the brain, can be treated with surgery early in a child’s life.

David G. McLone is a professor of neurological surgery, a physician at Children’s Memorial Hospital and a researcher at the Children’s Memorial Institute for Education and Research. Joel Charrow is an associate professor of pediatrics and a researcher at the Children’s Memorial Institute for Education and Research. John F. Sarwark is an associate professor of orthopedic surgery at the Medical School and a physician at Children’s Memorial Hospital. Marcy Speer is a basic scientist at Duke University Medical Center.