Chromosome 22 (human)

In the human genome, chromosome 22 is the second smallest of the 23 chromosomes. It is an acrocentric chromosome with a satellite, found within group G of the human karyotype. As with all autosomes, somatic cells carry two copies of chromosome 22, while gametes carry only one copy. Chromosome 22 was originally identified as the smallest chromosome, but it was later realised that the smallest is in fact chromosome 21. The chromosomes weren't renumbered because of the popularity of 'trisomy 21' as an alternative name for Down's Syndrome.

Chromosome 22 is approximately 49 Mbp (million base pairs) in length, comprising ~1.5-2% of the haploid genome
Chromosome 22 has approximately 693 genes

Significant genes (and some related genetic diseases) on chromosome 22 include: