This site provides [1] information on Down syndrome, [2] raw data and supplementary information for Mao et al. (Genomics 2003 May, 81(5)) "Global up-regulation of chromosome 21 gene expression in the developing Down Syndrome brain" and [3] raw and supplementary data for Mao et al. (submitted, 2005), "Role of gene expression in the developing human Down syndrome brain and heart."