The Chromosome 18 Clinical Research Center at the Health Science Center began as a study of children who have deletions of a portion of Chromosome 18 (18q-). The center got its start largely because of the dedication and perseverance of Jannine Cody, whose daughter, Elizabeth, has such a deletion. Jannine could not accept that there was nothing available to help Elizabeth. She determined to assist her own family and others by seeking her Ph.D. to study such abnormalities and by sharing a message of hope with parents.
Dr. Cody, now an associate professor in the Health Science Center’s department of pediatrics, formed the Chromosome 18 Registry & Research Society, a genetic advocacy group. Along the way, she met Brian and Suchada MacDonald, the Seattle-area parents of Acacia, also affected by an 18q deletion. The MacDonalds became the earliest and most significant supporters of the groundbreaking study to determine whether growth hormone, if given to children with 18q deletions, could result in positive changes in the children’s mental and physical states.
Two children, Elizabeth and Acacia, were the inspirations for the study that started 12 years ago. Since then, 25 researchers, most of whom are at the Health Science Center, have produced 21 scientific papers, and the study has involved 233 families.
Today, Elizabeth, 20, is a student at San Antonio College. Acacia, 13, is doing very well academically as she enters the seventh grade. Both received growth hormone therapy starting at a young age.
“This has made a huge difference for Acacia,” Brian MacDonald said. “Though she still faces challenges, she has tested out on the 80th percentile on a national assessment given to all students.”
Acacia is a voracious reader, especially of non-fiction, he said. She loves to talk about what she is reading, from Greek mythology and Roman history to the esoteric: seaweed of the Pacific. A typical teenage girl, she’s also becoming interested in fashion.
Children with 18q deletions have a deficiency in their ability to produce growth hormone and have other problems, including developmental delays, cognitive impairment and growth failure. Images of the children’s brains reveal a problem called dysmyelination, a failure of the myelin sheath to form completely. Myelin is a substance that covers the brain’s circuitry, much like insulation covers electric wiring. It makes information transfers between nerve cells more efficient.
The findings of the latest paper, published in the American Journal of American Genetics, are summed up in the title: “Growth hormone benefits children with 18q deletions.” The treated group of children showed an increase in height, an increase in nonverbal IQ, and changes in myelination as measured by magnetic resonance imaging (MRI) performed at the Health Science Center’s Research Imaging Center.
The MacDonalds and the other members of the Chromosome 18 Registry & Research Society have given support exceeding $3 million since the project began. Last year alone, the parents of the research society donated nearly $400,000. Dr. Cody and the other researchers have used that support as leverage to obtain grants from the National Institutes of Health.
Both Brian and Suchada MacDonald formerly worked for Microsoft Corp., and the company matched several of their first contributions to the project.
“If it hadn’t been for the MacDonalds, we would be nowhere,” Dr. Cody said. “When you start work on a condition that is virtually unstudied, how do you get started? You need people like Brian and Suchada and the members of the Chromosome 18 Registry & Research Society who have the vision that there is something that can be done to help their children. Today, things are different because of them.”
Annual meetings of the research society rotate among major cities of the United States, including San Antonio.
“The latest research paper represents the first report of a dramatic improvement of the cognitive defects associated with a chromosomal syndrome using growth hormone,” said Daniel Hale, M.D., professor of pediatrics and medical director of the Chromosome 18 Center.
Among the children on growth hormone who have undergone extensive follow-up assessments for several years, most showed substantial increases in nonverbal IQ. Those children who showed an increase had an average improvement of 28 points. Normal IQ scores range between 70 and 130, with the average being 100 in typical individuals. “To take a child from a nonverbal IQ of 65 to a score of 93 takes that individual from being an adult living in a group home to being able to get a college education and live independently,” Dr. Hale noted.
One of the other children on growth hormone is autistic, and because of behavioral issues is not IQ-testable. Two other children fall below the IQ rating floor of 50, and because of that, their improvement is not measurable. “Their parents kept them on growth hormone because they were thrilled with the alertness and strength they saw in their children,” Dr. Cody said. “Profoundly impaired children often do not walk or express themselves. Though we can’t measure it, these two children may have improved the most of all.”
The next meeting of the Chromosome 18 Registry & Research Society is July 5 -8, 2006, in Anaheim Calif. For more information on chromosome 18 syndromes, current research and the society, visitwww.chromosome18.org.