Chromosome 20 Explained

Length Bp:66,210,255 bp
(CHM13)
Genes:516 (CCDS)
Type:Autosome
Centromere Position:Metacentric[1]
(28.1 Mbp[2])
Chr:20
Ensembl Id:20
Entrez Id:20
Ncbi Id:20
Ucsc Id:20
Refseq Id:NC_000020
Genbank Id:CM000682

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.[3] Since then, due to sequencing improvements and fixes, the length of chromosome 20 has been updated to just over 66 million base pairs.[4]

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.[5]

Estimated byProtein-coding genesNon-coding RNA genesPseudogenesSourceRelease date
516 — —[6] 2016-09-08
HGNC519 191 297[7] 2017-05-12
540 594 247[8] 2017-03-29
550 — —[9] 2018-02-28
555 487 333[10] [11] [12] 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.

Diseases and disorders

The following diseases are some of those related to genes on chromosome 20:[13]

Cytogenetic band

G-bands of human chromosome 20 in resolution 850 bphs[14] ! Chr. ! Arm[15] ! Band[16] ! ISCN
start[17] ! ISCN
stop! Basepair
start ! Basepair
stop ! Stain[18] ! Density
20 p 13 0 333 gneg
20 p 12.3 333 513 gpos 75
20 p 12.2 513 624 gneg
20 p 12.1 624 915 gpos 75
20 p 11.23 915 1164 gneg
20 p 11.22 1164 1275 gpos 25
20 p 11.21 1275 1441 gneg
20 p 11.1 1441 1608 acen
20 q 11.1 1608 1774 acen
20 q 11.21 1774 1927 gneg
20 q 11.22 1927 2051 gpos 25
20 q 11.23 2051 2232 gneg
20 q 12 2232 2439 gpos 75
20 q 13.11 2439 2578 gneg
20 q 13.12 2578 2758 gpos 25
20 q 13.13 2758 3077 gneg
20 q 13.2 3077 3299 gpos 75
20 q 13.31 3299 3382 gneg
20 q 13.32 3382 3493 gpos 50
20 q 13.33 3493 3770 gneg

External links

Notes and References

  1. Book: Tom Strachan. Andrew Read. Human Molecular Genetics. 2 April 2010. Garland Science. 978-1-136-84407-2. 45.
  2. Genome Decoration Page, NCBI. Ideogram data for Homo sapience (850 bphs, Assembly GRCh38.p3). Last update 2014-06-03. Retrieved 2017-04-26.
  3. Deloukas P . The DNA sequence and comparative analysis of human chromosome 20 . Nature . 2001 . 865–871 . 414 . 6866 . 11780052 . 10.1038/414865a. 2001Natur.414..865D . etal. free .
  4. Web site: Homo sapiens chromosome 20, GRCh37.p13 Primary Assembly . National Center for Biotechnology Information . October 17, 2013.
  5. Pertea M, Salzberg SL. Between a chicken and a grape: estimating the number of human genes. . Genome Biol . 2010 . 11 . 5 . 206 . 20441615 . 10.1186/gb-2010-11-5-206 . 2898077 . free .
  6. Web site: Search results - 20[CHR] AND "Homo sapiens"[Organism] AND ("has ccds"[Properties] AND alive[prop]) - Gene . NCBI . CCDS Release 20 for Homo sapiens . 2016-09-08 . 2017-05-28.
  7. Web site: Statistics & Downloads for chromosome 20 . HUGO Gene Nomenclature Committee . 2017-05-12 . 2017-05-19.
  8. Web site: Chromosome 20: Chromosome summary - Homo sapiens . Ensembl Release 88 . 2017-03-29 . 2017-05-19.
  9. Web site: Human chromosome 20: entries, gene names and cross-references to MIM . UniProt . 2018-02-28 . 2018-03-16.
  10. Web site: Search results - 20[CHR] AND "Homo sapiens"[Organism] AND ("genetype protein coding"[Properties] AND alive[prop]) - Gene . NCBI . 2017-05-19 . 2017-05-20.
  11. Web site: Search results - 20[CHR] AND "Homo sapiens"[Organism] AND (("genetype miscrna"[Properties] OR "genetype ncrna"[Properties] OR "genetype rrna"[Properties] OR "genetype trna"[Properties] OR "genetype scrna"[Properties] OR "genetype snrna"[Properties] OR "genetype snorna"[Properties]) NOT "genetype protein coding"[Properties] AND alive[prop]) - Gene . NCBI . 2017-05-19 . 2017-05-20.
  12. Web site: Search results - 20[CHR] AND "Homo sapiens"[Organism] AND ("genetype pseudo"[Properties] AND alive[prop]) - Gene . NCBI . 2017-05-19 . 2017-05-20.
  13. Gilbert F . Disease genes and chromosomes: disease maps of the human genome . Genet Test . 1997 . 225–229 . 1 . 3 . 10464650 . 10.1089/gte.1997.1.225.
  14. Genome Decoration Page, NCBI. Ideogram data for Homo sapience (850 bphs, Assembly GRCh38.p3). Last update 2014-06-03. Retrieved 2017-04-26.
  15. "p": Short arm; "q": Long arm.
  16. For cytogenetic banding nomenclature, see article locus.
  17. These values (ISCN start/stop) are based on the length of bands/ideograms from the ISCN book, An International System for Human Cytogenetic Nomenclature (2013). Arbitrary unit.
  18. gpos: Region which is positively stained by G banding, generally AT-rich and gene poor; gneg: Region which is negatively stained by G banding, generally CG-rich and gene rich; acen Centromere. var: Variable region; stalk: Stalk.

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