Scientists, enabled by the Human Genome Project, are churning out an unprecedented volume of data on human chromosomes and the tens of thousands of genes residing on them, many associated with genetic disorders. These data, and many Web sites on human genetic disorders, are freely accessible on the Internet.
Genetic disorders associated with Chromosome 22.
Chromosome 22 is one of the 23 pairs of chromosomes in humans. People normally have two copies of Chromosome 22. Chromosome 22 is the second smallest human chromosome, spanning about 49 million base pairs (the building material of DNA) and representing between 1.5 and 2 % of the total DNA in cells.
In 1999, researchers working on the Human Genome Project announced they had determined the sequence of base pairs that make up this chromosome. Chromosome 22 was the first human chromosome to be fully sequenced.
Identifying genes on each chromosome is an active area of genetic research. Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. Chromosome 22 likely contains between 500 and 800 genes.