Chromosome 22 is one of the 23 pairs of chromosomes in human cells. Humans normally have two copies of chromosome 22 in each cell. Chromosome 22 is the second smallest human chromosome, spanning about 51 million DNA base pairs and representing between 1.5 and 2% of the total DNA in cells.
Chromosome 22 | |
---|---|
Features | |
Length (bp) | 51,324,926 bp (CHM13) |
No. of genes | 417 (CCDS)[1] |
Type | Autosome |
Centromere position | Acrocentric[2] (15.0 Mbp[3]) |
Complete gene lists | |
CCDS | Gene list |
HGNC | Gene list |
UniProt | Gene list |
NCBI | Gene list |
External map viewers | |
Ensembl | Chromosome 22 |
Entrez | Chromosome 22 |
NCBI | Chromosome 22 |
UCSC | Chromosome 22 |
Full DNA sequences | |
RefSeq | NC_000022 (FASTA) |
GenBank | CM000684 (FASTA) |
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.[4]
Human chromosomes are numbered by their apparent size in the karyotype, with chromosome 1 being the largest and chromosome 22 having originally been identified as the smallest. However, genome sequencing has revealed that chromosome 21 is actually smaller than chromosome 22.
The following are some of the gene count estimates of human chromosome 22. Because researchers use different approaches to genome annotation, their predictions of the number of genes on each chromosome varies (for technical details, see gene prediction). 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.[5]
Estimated by | Protein-coding genes | Non-coding RNA genes | Pseudogenes | Source | Release date |
---|---|---|---|---|---|
CCDS | 417 | — | — | [1] | 2016-09-08 |
HGNC | 424 | 161 | 295 | [6] | 2019-07-08 |
Ensembl | 489 | 515 | 325 | [7] | 2017-03-29 |
UniProt | 496 | — | — | [8] | 2018-02-28 |
NCBI | 474 | 392 | 379 | [9][10][11] | 2017-05-19 |
The following is a partial list of genes on human chromosome 22. For complete list, see the link in the infobox on the right.
Locus | Gene | Description | Condition |
22q11.1-q11.2 | IGL@ | Asymmetric crying facies (Cayler cardiofacial syndrome) | |
22q11.21 | TBX1 | T-box 1 | |
22q11 | RTN4R | Reticulon 4 receptor | Schizophrenia |
22q11.21-q11.23 | COMT | catechol-O-methyltransferase gene | |
22q12.1-q13.1 | NEFH | neurofilament, heavy polypeptide 200kDa | |
22q12.1[12] | CHEK2 | CHK2 checkpoint homolog (S. pombe) | |
22q12.2 | NF2 | neurofibromin 2 | bilateral acoustic neuroma |
22q13 | SOX10 | SRY (sex determining region Y)-box 10 | |
22q13.1 | APOL1 | Apolipoprotein L1 | |
22q13.2 | EP300 | E1A binding protein p300 | |
22q13.3 | WNT7B | Wingless-type MMTV integration site family, member 7B | 22q13 deletion syndrome |
22q13.3 | SHANK3 | SH3 and multiple ankyrin repeat domains 3 | 22q13 deletion syndrome |
22q13.3 | SULT4A1 | sulfotransferase family 4A, member 1 | 22q13 deletion syndrome |
22q13.3 | PARVB | parvin beta (cytoskeleton organization and cell adhesion) | 22q13 deletion syndrome |
The following diseases are some of those related to genes on chromosome 22:
The following conditions are caused by changes in the structure or number of copies of chromosome 22:
Chr. | Arm[18] | Band[19] | ISCN start[20] |
ISCN stop[20] |
Basepair start |
Basepair stop |
Stain[21] | Density |
---|---|---|---|---|---|---|---|---|
22 | p | 13 | 0 | 260 | 1 | 4,300,000 | gvar | |
22 | p | 12 | 260 | 576 | 4,300,001 | 9,400,000 | stalk | |
22 | p | 11.2 | 576 | 836 | 9,400,001 | 13,700,000 | gvar | |
22 | p | 11.1 | 836 | 1015 | 13,700,001 | 15,000,000 | acen | |
22 | q | 11.1 | 1015 | 1234 | 15,000,001 | 17,400,000 | acen | |
22 | q | 11.21 | 1234 | 1563 | 17,400,001 | 21,700,000 | gneg | |
22 | q | 11.22 | 1563 | 1700 | 21,700,001 | 23,100,000 | gpos | 25 |
22 | q | 11.23 | 1700 | 1878 | 23,100,001 | 25,500,000 | gneg | |
22 | q | 12.1 | 1878 | 2029 | 25,500,001 | 29,200,000 | gpos | 50 |
22 | q | 12.2 | 2029 | 2194 | 29,200,001 | 31,800,000 | gneg | |
22 | q | 12.3 | 2194 | 2413 | 31,800,001 | 37,200,000 | gpos | 50 |
22 | q | 13.1 | 2413 | 2687 | 37,200,001 | 40,600,000 | gneg | |
22 | q | 13.2 | 2687 | 2852 | 40,600,001 | 43,800,000 | gpos | 50 |
22 | q | 13.31 | 2852 | 3181 | 43,800,001 | 48,100,000 | gneg | |
22 | q | 13.32 | 3181 | 3290 | 48,100,001 | 49,100,000 | gpos | 50 |
22 | q | 13.33 | 3290 | 3400 | 49,100,001 | 50,818,468 | gneg |