By Tom Interval
Staff Writer
Two weeks after Angie McCoy, an expectant mother, had a blood test done at Magee-Womens hospital, a concerned doctor called and said he wanted to schedule a follow-up exam.
After performing an ultrasound, the doctor told McCoy and her husband, Mark, that their unborn son has spina bifida.
“We were fearful. We didn’t know if he was going to die,” said Mrs. McCoy.
The McCoys’ son, Daniel, was born January 24. He is one of an estimated 1,500 people in Western Pennsylvania who has spina bifida.
Although no one knows what causes spina bifida, there have been many theories. One of the more recent ones will be studied at La Roche College in the coming months.
Jonathan Bennett, a chemistry major and senior at La Roche, is developing a clinical test that could help shed light on whether or not women who are deficient in folic acid during pregnancy are at greater risk of having a child with spina bifida. Folic acid, a B-complex vitamin, is the synthetic form of folate, which is found naturally in leafy green vegetables, citrus fruits, beans and fortified breakfast cereals.
So far, there is no conclusive evidence that links spina bifida with folic acid deficiencies, according to Bennett’s advisor, Dr. Don Fujito, assistant professor of chemistry at La Roche.
“[The test Bennett is developing] is not the definitive answer. We want to supply one piece of the puzzle,” says Dr. Fujito.
Spina bifida is the most common disabling birth defect in the United States, affecting between one and two infants out of every 1,000 born, according to the Spina Bifida Association of Western Pennsylvania (SBAWP). The defect occurs in the first month of pregnancy, sometimes before the mother even knows she is pregnant.
Often referred to as a neural tube defect, or NTD, spina bifida takes on two major forms: spina bifida occulta and spina bifida cystica.
Spina bifida occulta, which is found in about a third of the population, refers to a defect, or gap, in one of the bones of the vertebrae. Some people have this form of spina bifida and don’t even know it, according to SBAWP literature.
Spina bifida cystica is the form relevant to Bennett’s research and is the type that often causes lower-body paralysis, foot and knee deformities and chronic bladder and kidney problems. Hydrocephalus, an accumulation of cerebrospinal fluid surrounding the brain, often accompanies spina bifida cystica. People with this type of spina bifida sometimes have learning disabilities, and about 30 percent of children with the defect have slight to severe mental retardation, according to an article in the May 1994 issue of FDA Consumer.
Spina bifida cystica’s three basic conditions, which are myelomeningocele, meningomyelocele and myelodysplasia, usually involve a birth defect in which there is a sac or cyst protruding from the infant’s back (usually the lower back). The sac contains a portion of the spinal cord, nerves and spinal fluid (often called cerebrospinal fluid, or, CSF). Most nerves going to and from this area of the back do not function properly. The number of complications the child will experience depends on the extent of nerve damage.
Usually within 24 hours after birth, surgery takes place, during which the neurosurgeon repairs and closes the baby’s back. It is from this operation that cerebrospinal fluid samples, which might contain certain amounts of folic acid, can be taken for research purposes.
The research a La Roche would involve analysis of spinal fluid from at least 100 spina bifida patients from Allegheny General Hospital. Donald H. Reigel, M.D., director of pediatric neurosurgery at AGH and SBAWP chairman of the board, will obtain the samples.
Bennett, 22, says researchers have not yet examined spinal fluid samples from actual patients with spina bifida.
“All studies that we have seen looked at the folic acid of the mother, so this is a little bit different,” he says.
When the samples arrive, Bennett plans to use sophisticated equipment that will detect the levels of six chemicals in the spinal fluid: folic acid and five folic-acid derivatives. The technology used to analyze the six compounds is called High-Performance Liquid Chromatography, or HPLC. The HPLC machine, located in the instrumentation lab at La Roche, would uncover three things: which chemicals, if any, are present in the spinal fluid, the total amount of those chemicals and how much of each compound is present. The HPLC machine would be connected to a device called an autosampler, which would allow Bennett to conduct tests on several samples at once.
“What I’ll be able to do is put maybe 100 samples in the autosampler, program the computer, start it on a Friday afternoon, come back Monday morning and it’ll be done,” says Bennett.
The final data from the spinal tap analysis will be produced on an instrument called a Diode Array Spectrophotometer. The data would be in the form of printed line graphs representing each sample. The graphs would be compared with data from spinal taps obtained from patients who do not have spina bifida. Bennett says the main objective of the test is to see if the metabolism of folic acid (how folic acid is chemically changed in the body) is significantly altered in the patient with spina bifida.
The result of the test might help to prove or disprove a relationship between spina bifida and folic acid deficiencies in pregnant women, according to Dr. Fujito.
Bennett and Dr. Fujito will not receive samples from AGH until the initial parameters for the test are set. Currently, Bennett is entering data into the HPLC machine, which would help the device identify folic acid compounds during actual testing of spinal.
Bennett, who will receive seven credits for his participation in the research, must write a thesis on his findings. Dr. Fujito says Bennett is getting the chemistry foundation he needs as well as having the opportunity to work on something with clinical relevance.
“I wish I had this chance when I was an undergrad,” says Dr. Fujito.
