# Chromosome 20

Chromosome 20 is one of the 23 pairs of chromosomes in humans. Chromosome 20 spans around 66 million base pairs (the building material of DNA) and represents between 2 and 2.5 percent of the total DNA in cells. Chromosome 20 was fully sequenced in 2001 and was reported to contain over 59 million base pairs. Since then, due to sequencing improvements and fixes, the length of chromosome 20 has been updated to just over 66 million base pairs.

## Genes
### Number of genes

The following are some of the gene count estimates of human chromosome 20. 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.
| Estimated by | Protein-coding genes | Non-coding RNA genes | Pseudogenes | Release date |
| CCDS | 516 | — | — | 2016-09-08 |
| HGNC | 519 | 191 | 297 | 2017-05-12 |
| Ensembl | 540 | 594 | 247 | 2017-03-29 |
| UniProt | 550 | — | — | 2018-02-28 |
| NCBI | 555 | 487 | 333 | 2017-05-19 |

### Gene list

The following is a partial list of genes on human chromosome 20. For complete list, see the link in the infobox on the right.
* ADA: Adenosine Deaminase (Adenosine Deaminase Deficiency)
* ANDP: encoding protein Activity-dependent neuroprotector homeobox
* AHCY: S-adenosylhomocysteine hydrolase
* APMAP: encoding protein Adipocyte plasma membrane-associated protein
* ARFGEF2: ADP-ribosylation factor guanine nucleotide-exchange factor 2 (brefeldin A-inhibited)
* BCAS1: Breast carcinoma-amplified sequence 1
* BLCAP: Bladder cancer associated protein
* BMP2: Bone Morphogenetic Protein 2 (osteoblast differentiation)
* BPIFA1: encoding protein BPI fold containing family A, member 1
* BPIFA2: encoding protein BPI fold containing family A, member 2
* BPIFA3: encoding protein BPI fold containing family A, member 3
* BPIFA4P: non-coding pseudogene of the BPI fold containing family A, member 4P
* BPIFB1: encoding protein BPI fold containing family B, member 1
* BPIFB2: encoding protein BPI fold containing family B, member 2
* BPIFB3: encoding protein BPI fold containing family B, member 3
* BPIFB4: encoding protein BPI fold containing family B, member 4
* BPIFB5P: non-coding pseudogene of the BPI fold containing family B, member 5P
* BPIFB6: encoding protein BPI fold containing family B, member 6
* BPIFB9P: non-coding pseudogene of the BPI fold containing family B, member 9P
* C20orf27: encoding protein UPF0687 protein C20orf27
* CSRP2BP: encoding protein CSRP2 binding protein
* CST9L: Cystatin-9-like
* CSTL1: Cystatin-like 1
* CTCFL: CCCTC-binding factor-like
* CTNNBL1: Beta-catenin-like protein 1
* DBNDD2: Dysbindin domain-containing protein 2
* DDX27: DEAD box polypeptide 27
* DEFB118, DEFB119, DEFB126, DEFB127, DEFB129: Beta-defensin genes
* DLGAP4: Disks large-associated protein 4
* DNAJC5: Cysteine string protein
* EDEM2: ER degradation-enhancing alpha-mannosidase-like 2
* EDN3: endothelin 3
* ENTPD6: Ectonucleoside triphosphate diphosphohydrolase 6
* ESF1: ESF1 nucleolar pre-rRNA processing protein homolog
* FAM210B: encoding protein FAM210B
* FASTKD5: encoding protein FAST kinase domain-containing protein 5 (FASTKD5)
* FITM2: encoding protein Fat storage-inducing transmembrane protein 2
* GZF1: encoding protein GDNF-inducible zinc finger protein 1
* GMEB2: Glucocorticoid modulatory element-binding protein 2
* GNAS1: Gs alpha subunit (membrane G-protein)
* GSS: glutathione synthetase
* HSPA12B: encoding protein Heat shock protein family a (hsp70) member 12b
* ITPA: encoding enzyme Inosine triphosphate pyrophosphatase
* JAG1: jagged 1 (Alagille syndrome)
* JPH2: encoding protein Junctophilin 2
* KIAA1755: encoding protein Kiaa1755
* KIZ: encoding protein Kizuna centrosomal protein
* Kua-UEV:
* L3MBTL: encoding protein Lethal(3)malignant brain tumor-like protein
* LIME1: encoding protein Lck-interacting transmembrane adapter 1
* LZTS3: encoding protein Leucine zipper, putative tumor suppressor family member 3
* MIR124-3: encoding protein MIR124-3
* MIR499A: encoding protein MicroRNA 499a
* MROH8: encoding protein maestro heat like repeat family member 8
* NAPB: encoding protein Beta-soluble NSF attachment protein
* NDUFAF5: encoding protein NADH:ubiquinone oxidoreductase complex assembly factor 5
* Nnat: encoding protein Neuronatin
* NOL5A: encoding protein Nucleolar protein 56
* NRSN2: encoding protein Neurensin-2
* OCSTAMP: encoding protein Osteoclast stimulatory transmembrane protein
* OTOR: encoding protein Otoraplin
* OXT: encoding protein Oxytocin/neurophysin i prepropeptide
* PANK2: pantothenate kinase 2 (pantothenate kinase-associated neurodegeneration)
* PKIG: encoding protein cAMP-dependent protein kinase inhibitor gamma
* PLAGL2: encoding protein Zinc finger protein PLAGL2
* POLR3F: encoding enzyme DNA-directed RNA polymerase III subunit RPC6
* PRIC285:
* PRNP: prion protein (p27-30) (Creutzfeldt–Jakob disease, Gerstmann-Strausler-Scheinker syndrome, fatal familial insomnia)
* PXMP4: encoding protein Peroxisomal membrane protein 4
* R3HDML: encoding protein R3H domain containing-like
* RTF2: encoding protein RTF2 homolog
* SALL4: sal-like 4 (Drosophila)
* SERINC3: encoding protein Serine incorporator 3
* SHLD1: encoding protein Shieldin complex subunit 1
* SLC17A9: encoding protein Solute carrier family 17 member 9
* SLC2A4RG: encoding protein SLC2A4 regulator
* SLX4IP: encoding protein SLX4 interacting protein
* SNPH: encoding protein Syntaphilin
* SPATA2: encoding protein Spermatogenesis-associated protein 2
* SPEF1: encoding protein Sperm flagellar protein 1
* SRXN1: encoding protein Sulfiredoxin-1
* STAU1: encoding protein Double-stranded RNA-binding protein Staufen homolog 1
* STK35L1: encoding protein STK35L1
* SUN5: encoding protein SUN domain-containing protein 5
* TASP1: encoding enzyme Threonine aspartase 1
* tTG: tissue transglutaminase (auto antigen of Celiac disease)
* TMEPAI: encoding protein Transmembrane prostate androgen-induced protein
* TTPAL: encoding protein Tocopherol (alpha) transfer protein-like
* UCKL1: encoding enzyme Uridine-cytidine kinase-like 1
* UQCC: encoding enzyme Ubiquinol-cytochrome c reductase complex chaperone CBP3 homolog
* VAPB: VAMP (vesicle-associated membrane protein)-associated protein B and C
* YTHDF1: encoding protein YTH domain family, member 1
* ZFP64 encoding protein Zinc finger protein 64 homolog, isoforms 1 and 2
* ZGPAT: encoding protein Zinc finger CCCH-type with G patch domain-containing protein
* ZHX3: encoding protein Zinc fingers and homeoboxes protein 3
* ZNF334: encoding protein Zinc finger protein 334
* ZNF343: encoding protein Zinc finger protein 343
* ZSWIM3: encoding protein Zinc finger SWIM-type containing 3
* ZMYND8: encoding enzyme Protein kinase C-binding protein 1
* ZNF133: encoding protein Zinc finger protein 133

## Diseases and disorders

The following diseases are some of those related to genes on chromosome 20:
* Albright's hereditary osteodystrophy
* Arterial tortuosity syndrome
* Adenosine deaminase deficiency
* Alagille syndrome
* Galactosialidosis - CTSA
* Maturity onset diabetes of the young type 1
* Neuronal ceroid lipofuscinosis
* Pantothenate kinase-associated neurodegeneration
* Waardenburg syndrome
* CARASAL

## Cytogenetic band

G-bands of human chromosome 20 in resolution 850 bphs :
| Chr. | Arm | Band | ISCN start | ISCN stop | Basepair start | Basepair stop | Stain | Density |
| 20 | p | 13 | 0 | 333 | 1 | 5,100,000 | gneg | |
| 20 | p | 12.3 | 333 | 513 | 5,100,001 | 9,200,000 | gpos | 75 |
| 20 | p | 12.2 | 513 | 624 | 9,200,001 | 12,000,000 | gneg | |
| 20 | p | 12.1 | 624 | 915 | 12,000,001 | 17,900,000 | gpos | 75 |
| 20 | p | 11.23 | 915 | 1164 | 17,900,001 | 21,300,000 | gneg | |
| 20 | p | 11.22 | 1164 | 1275 | 21,300,001 | 22,300,000 | gpos | 25 |
| 20 | p | 11.21 | 1275 | 1441 | 22,300,001 | 25,700,000 | gneg | |
| 20 | p | 11.1 | 1441 | 1608 | 25,700,001 | 28,100,000 | acen | |
| 20 | q | 11.1 | 1608 | 1774 | 28,100,001 | 30,400,000 | acen | |
| 20 | q | 11.21 | 1774 | 1927 | 30,400,001 | 33,500,000 | gneg | |
| 20 | q | 11.22 | 1927 | 2051 | 33,500,001 | 35,800,000 | gpos | 25 |
| 20 | q | 11.23 | 2051 | 2232 | 35,800,001 | 39,000,000 | gneg | |
| 20 | q | 12 | 2232 | 2439 | 39,000,001 | 43,100,000 | gpos | 75 |
| 20 | q | 13.11 | 2439 | 2578 | 43,100,001 | 43,500,000 | gneg | |
| 20 | q | 13.12 | 2578 | 2758 | 43,500,001 | 47,800,000 | gpos | 25 |
| 20 | q | 13.13 | 2758 | 3077 | 47,800,001 | 51,200,000 | gneg | |
| 20 | q | 13.2 | 3077 | 3299 | 51,200,001 | 56,400,000 | gpos | 75 |
| 20 | q | 13.31 | 3299 | 3382 | 56,400,001 | 57,800,000 | gneg | |
| 20 | q | 13.32 | 3382 | 3493 | 57,800,001 | 59,700,000 | gpos | 50 |
| 20 | q | 13.33 | 3493 | 3770 | 59,700,001 | 64,444,167 | gneg | |