Chromosome 18 Explained

Length Bp:	80,542,538 bp (CHM13)
Genes:	261 (CCDS)
Type:	Autosome
Centromere Position:	Submetacentric^[1] (18.5 Mbp^[2])
Chr:	18
Ensembl Id:	18
Entrez Id:	18
Ncbi Id:	18
Ucsc Id:	18
Refseq Id:	NC_000018
Genbank Id:	CM000680

Chromosome 18 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 18 spans about 80 million base pairs (the building material of DNA) and represents about 2.5 percent of the total DNA in cells.

Genes

Number of genes

The following are some of the gene count estimates of human chromosome 18. 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.^[3]

Estimated by	Protein-coding genes	Non-coding RNA genes	Pseudogenes	Source	Release date
	261	—	—	^[4]	2016-09-08
HGNC	262	138	241	^[5]	2017-05-12
	268	608	247	^[6]	2017-03-29
	276	—	—	^[7]	2018-02-28
	285	432	304	^[8] ^[9] ^[10]	2017-05-19

Gene list

The following is a partial list of genes on human chromosome 18. 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 18:

• Erythropoietic protoporphyria
• Hereditary hemorrhagic telangiectasia
• Niemann–Pick disease type C
• Porphyria
• Selective mutism
• Edwards syndrome (trisomy 18)
• Tetrasomy 18p
• Monosomy 18p
• Pitt–Hopkins syndrome 18q21
• Distal 18q- (distal deletion)^[11]
• Proximal 18q- (proximal deletion)

Cytogenetic band

G-bands of human chromosome 18 in resolution 850 bphs^[12] ! Chr. ! Arm^[13] ! Band^[14] ! ISCN
start^[15] ! ISCN
stop! Basepair
start ! Basepair
stop ! Stain^[16] ! Density

18	p	11.32	0	159			gneg
18	p	11.31	159	430			gpos	50
18	p	11.23	430	526			gneg
18	p	11.22	526	685			gpos	25
18	p	11.21	685	1035			gneg
18	p	11.1	1035	1290			acen
18	q	11.1	1290	1561			acen
18	q	11.2	1561	1847			gneg
18	q	12.1	1847	2229			gpos	100
18	q	12.2	2229	2436			gneg
18	q	12.3	2436	2755			gpos	75
18	q	21.1	2755	3153			gneg
18	q	21.2	3153	3392			gpos	75
18	q	21.31	3392	3519			gneg
18	q	21.32	3519	3663			gpos	50
18	q	21.33	3663	3758			gneg
18	q	22.1	3758	4077			gpos	100
18	q	22.2	4077	4204			gneg
18	q	22.3	4204	4411			gpos	25
18	q	23	4411	4650			gneg

References

• Nusbaum C, Zody MC, Borowsky ML, Kamal M, Kodira CD, Taylor TD, Whittaker CA, Chang JL, Cuomo CA, Dewar K, FitzGerald MG, Yang X, Abouelleil A, Allen NR, Anderson S, Bloom T, Bugalter B, Butler J, Cook A, DeCaprio D, Engels R, Garber M, Gnirke A, Hafez N, Hall JL, Norman CH, Itoh T, Jaffe DB, Kuroki Y, Lehoczky J, Lui A, Macdonald P, Mauceli E, Mikkelsen TS, Naylor JW, Nicol R, Nguyen C, Noguchi H, O'Leary SB, O'Neill K, Piqani B, Smith CL, Talamas JA, Topham K, Totoki Y, Toyoda A, Wain HM, Young SK, Zeng Q, Zimmer AR, Fujiyama A, Hattori M, Birren BW, Sakaki Y, Lander ES . DNA sequence and analysis of human chromosome 18 . Nature . 2005 . 551–5 . 437 . 7058 . 16177791 . 10.1038/nature03983. 2005Natur.437..551N . free .
• Chen H, Wang N, Huo Y, Sklar P, MacKinnon DF, Potash JB, McMahon FJ, Antonarakis SE, ((DePaulo JR Jr)), Ross CA, McInnis MG . Trapping and sequence analysis of 1138 putative exons from human chromosome 18 . Mol Psychiatry . 2003 . 619–23 . 8 . 6 . 12851638 . 10.1038/sj.mp.4001288. free .
• Gilbert F . Disease genes and chromosomes: disease maps of the human genome. Chromosome 18 . Genet Test . 1997 . 69–71 . 1 . 1 . 10.1089/gte.1997.1.69 . 10464628.

External links

• Chromosome18.org
• Chromosome18 Registry And Research Society in Europe.
• Web site: National Institutes of Health . Chromosome 18 . Genetics Home Reference . https://web.archive.org/web/20040803051751/http://ghr.nlm.nih.gov/chromosome=18 . dead . August 3, 2004 . 2017-05-06 .
• Web site: Chromosome 18. Human Genome Project Information Archive 1990–2003. 2017-05-06.

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. 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 .
4. Web site: Search results - 18[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.
5. Web site: Statistics & Downloads for chromosome 18 . HUGO Gene Nomenclature Committee . 2017-05-12 . 2017-05-19 . 2017-06-29 . https://web.archive.org/web/20170629091158/http://www.genenames.org/cgi-bin/statistics?c=18 . dead .
6. Web site: Chromosome 18: Chromosome summary - Homo sapiens . Ensembl Release 88 . 2017-03-29 . 2017-05-19.
7. Web site: Human chromosome 18: entries, gene names and cross-references to MIM . UniProt . 2018-02-28 . 2018-03-16.
8. Web site: Search results - 18[CHR] AND "Homo sapiens"[Organism] AND ("genetype protein coding"[Properties] AND alive[prop]) - Gene . NCBI . 2017-05-19 . 2017-05-20.
9. Web site: Search results - 18[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.
10. Web site: Search results - 18[CHR] AND "Homo sapiens"[Organism] AND ("genetype pseudo"[Properties] AND alive[prop]) - Gene . NCBI . 2017-05-19 . 2017-05-20.
11. Web site: chromosome18. www.chromosome18.org. en-US. 2017-01-19.
12. Genome Decoration Page, NCBI. Ideogram data for Homo sapience (850 bphs, Assembly GRCh38.p3). Last update 2014-06-03. Retrieved 2017-04-26.
13. "p": Short arm; "q": Long arm.
14. For cytogenetic banding nomenclature, see article locus.
15. 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.
16. 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.