When chromosomes, which are normally bar-shaped, instead bend into a ring before birth, they may disrupt normal development and cause a multitude of problems. Genetics experts at The Childrens Hospital of Philadelphia will be investigating one such disorder, supported by a $126,000 grant from the Ring Chromosome 20 Foundation.
Ring chromosome 20 syndrome, so-called because it affects the 20th of the 23 human chromosomes, often causes a severe form of epilepsy that is difficult to treat. First described in 1972, it is considered relatively rare. The actual prevalence is uncertain, because it may go undiagnosed in some patients with severe epilepsy, says Nancy B. Spinner, Ph.D., a geneticist at Childrens Hospital who leads the new project.
We believe that the abnormal ring shape that occurs in this disorder interferes with the normal function of genes on chromosome 20, leading to the pattern of abnormalities seen in patients, added Dr. Spinner. In addition to epilepsy, the symptoms, manifesting themselves in childhood or adolescence, may include mental retardation, growth disturbances and small head circumference.
The Ring Chromosome 20 program will initially identify patients with the syndrome, establish cell lines and a clinical database, map the chromosome and analyze patterns of gene expression, in building a knowledge foundation for eventually guiding the way to future treatments for the disorder.
Dr. Spinner, the director of the Clinical Cytogenetics Laboratory at Childrens Hospital, previously discovered genes responsible for the genetic disease Alagille syndrome, which affects multiple organs. Childrens Hospital has one of the worlds leading programs for the diagnosis and treatment of genetic diseases in children.
Dr. Spinner will be collaborating with the hospitals new Center for Applied Genomics to better define the molecular defects occurring in ring chromosome 20 syndrome. Established in July 2006, the center is the worlds largest program dedicated to genetic analysis of childhood diseases. After we understand the underlying molecular processes, we hope this will lead to the development of potential treatments for the syndrome, said Dr. Spinner, who is a professor of Human Genetics in Pediatrics at the University of Pennsylvania School of Medicine.
|Contact: John Ascenzi|
Children's Hospital of Philadelphia