Chromosome 21 is one of the smallest among the 23 different human chromosomes. It is associated with Trisomy 21, one of the most common genetic diseases (also known as Down syndrome). An extra copy of chromosome 21 results in severely aberrant physical and mental development in children, leading to mental retardation. The disease affects up to 1 in 700 live births. An international collaborative group led by German and Japanese scientists will publish the sequence of chromosome 21 in the journal Nature (18th May 2,000). This work will be freely available on the Nature website from the 8th May. With these findings, the scientists deliver the key for a deeper understanding of the molecular mechanisms of trisomy 21 and other diseases involving chromosome 21, as well as for the design of novel diagnostic tools.
After the successful sequencing of chromosome 22 in December 1999 by a group of international scientists, chromosome 21 is now the second human chromosome which has been deciphered completely. Virtually all genes encoded by chromosome 21 have now been identified by computer-based analysis of the genomic sequence. This tremendous scientific effort was achieved by an international cooperation of scientists from 5 institutions: RIKEN genomic science center, Sagamihara (Japan), the Department of Molecular Biology of Keio University, Tokyo (Japan), the GBF-Gesellschaft fuer Biotechnologishe Forschung, Braunschweig (Germany), the Institut fuer Molekulare Biotechnologie (IMB), Jena (Germany), and the Max Planck Institute for Molecular Genetics, Berlin (Germany).
Historically, sequencing of chromosome 21 started in the early 90's. By 1995, the German-Japanese consortium was formed, with the aim of accomplishing the task of systematic sequencing of all of the 33.546.361 base pairs of chromosome 21. Altogether, a total of 170 people have worked on this international project. The German Ministry of Education and Science (BMBF) has financed the German groups
Contact: Dr. Jrg Wadzack