Source: Queen Mary, University of London
Date: 4 September 2008
Summary:
Scientists investigating the mechanisms of Down Syndrome (DS) have revealed the earliest developmental changes in embryonic stem cells caused by an extra copy of human chromosome 21 – the aberrant inheritance of which results in the condition. Their study is published online today (Thursday 4 September) in the American Journal of Human Genetics.
Lead by Dean Nizetic, Professor of Cellular and Molecular Biology at Barts and The London School of Medicine and Dentistry, the team utilised embryonic stem cells from a previously genetically engineered species of mice carrying a copy of human chromosome 21. They discovered that extra chromosome 21 - a genetic state known as trisomy 21 - disturbs a key regulating gene called NRSF or REST, which in turn disturbs the cascade of other genes that control normal development at the embryonic stem cell stage. Furthermore, they identified one gene (DYRK1A) on human chromosome 21, whose overdose in trisomy (DS), is responsible for the observed effects.
