Cardiovascular Genomics: Estimating the Total Number of Genes Expressed in the Human Cardiovascular System

The number of genes encoded by the human genome has long sought to be determined. With the recent publications of the complete sequence of the human genome, the number of genes encoded by the human genome has now been estimated to be 32 000–38 000. Now the next step will be to determine which of these genes are expressed in a given cell, tissue or organ. Using three unique approaches taking advantage of our current cardiovascular EST database and the complete nucleotide sequence of human chromosomes 21 and 22 as well as cDNA microarray hybridization, we estimate that between 20 930–27 160 genes are expressed in the cardiovascular system.