Structure of Human Chromosome 21—For an Understanding of Genetic Diseases Including Down’s Syndrome—

We do not intend to give information about the structure of human chromosome 21 in detail but to give a kind of perspective of the present status of our knowledge about human chromosome 21 in this article. Recent development of molecular biology has changed revolutionarily the status of our knowledge of the human chromosome in general. Therefore we will choose a few aspects of the development in this field and want to discuss how we are able to use such information to understand the genetic diseases including Down's syndrome.