Chromosome 2

Chromosome 2 is one of the twenty-three pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 2 is the second-largest human chromosome, spanning more than 242 million base pairs and representing almost eight percent of the total DNA in human cells.
Chromosome 2 contains the HOXD homeobox gene cluster.
Evolution.
Humans have only twenty-three pairs of chromosomes, while all other extant members of Hominidae have twenty-four pairs. (It is believed that Neanderthals and Denisovans had twenty-three pairs.) Human chromosome 2 is a result of an end-to-end fusion of two ancestral chromosomes.
The evidence for this includes:
Genes.
Number of genes.
The following are some of the gene count estimates of human chromosome 2. Because researchers use different approaches to genome annotation their predictions of the number of genes on each chromosome vary. Among various projects, the collaborative consensus coding sequence project (CCDS) takes an extremely conservative strategy. So CCDS's gene number prediction represents a lower bound on the total number of human protein-coding genes.
List of genes.
The following is a partial list of genes on human chromosome 2. For complete list, see the link in the infobox on the right.
p-arm.
Partial list of the genes located on p-arm (short arm) of human chromosome 2:
q-arm.
Partial list of the genes located on q-arm (long arm) of human chromosome 2:
Related disorders and traits.
The following diseases and traits are related to genes located on chromosome 2: