MADISON - Using stem cells as a window to the earliest developmental processes in the human brain, scientists have found that a group of genes critical for brain development is selectively disrupted in Down syndrome.
Writing in the recent issue (Jan. 26, 2002) of the British medical journal The Lancet, a team of scientists from the University of Cambridge, University College London and the University of Wisconsin-Madison report findings from a genetic study based on stem cells derived from Down syndrome and normal fetal tissue.
The results illuminate some of the key cellular and molecular processes that give rise to Down syndrome, one of the most common causes of developmental disability in humans. The study is the first of its kind using human cells.
The central finding of the study, according to Clive N. Svendsen, a UW-Madison professor of anatomy and neurology and a co-author of the report, is that a faulty genetic circuit results in dramatic changes in the development of the cells that make up the early brain.
"These findings point to a serious deficit in specific genes known to be important for neuronal development," said Svendsen who is currently director of the stem cell research program at the UW-Madison Waisman Center, one of the world's leading centers for the study of human development, developmental disabilities, and neurodegenerative diseases.
The Lancet study, which Svendsen co-authored with lead author Sabine Bahn, University of Cambridge, and others has begun to shed light on the earliest genetic events in humans that give rise to a serious cognitive disability.
It has long been known that most instances of Down syndrome, which affects nearly 350,000 people in the United States alone, results from an extra chromosome, chromosome 21, in the cells of those who have the condition. However, the precise genetic events that lead to the abnormal brain development of people with Down syndrome have not been u
Contact: Clive N. Svendsen
University of Wisconsin-Madison