Chromosome 6 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 6 spans nearly 171 million base pairs (the building material of DNA) and represents 5.5–6% of the total DNA in cells. It contains the major histocompatibility complex, which contains over 132 genes related to the immune response, and plays a vital role in organ transplantation.

The evolution of human centromere 6 The centromere of chromosome 6 illustrates an interesting example of centromere evolution. It was known that in a Catarrhini ancestor the chromosome 6 centromere was situated near position 28 Mb of the modern human chromosome. In Macaca mulatta, this old centromere went defunct and repositioned to a different chromosomal location. In the case of humans, the old centromere went defunct and a more recent form emerged near the modern position of human cen6 (size of 60 Mb). Such cases are known as Evolutionary New Centromeres (ENC). This assembly phenomenon of the human chromosome 6 gives researchers an opportunity to investigate the origin of the ENC on chromosome 6.

Genes The human leukocyte antigen lies on chromosome 6, with the exception of the gene for β2-microglobulin (which is located on chromosome 15), and encodes cell-surface antigen-presenting proteins among other functions.

Number of genes In 2003, the entirety of chromosome 6 was manually annotated for proteins, resulting in the identification of 1,557 genes, and 633 pseudogenes.

The following are some of the newer gene count estimates. 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 Source Release date CCDS 996 — — 2016-09-08 HGNC 1,007 422 736 2017-05-12 Ensembl 1,038 985 800 2017-03-29 UniProt 1,111 — — 2018-02-28 NCBI 1,053 1,188 911 2017-05-19

Gene list

The following is a partial list of genes on human chromosome 6.

p-arm The following are some of the genes located on p-arm (short arm) of human chromosome 6:

q-arm The following are some of the genes located on q-arm (long arm) of human chromosome 6:

Diseases and disorders The following diseases are some of those related to genes on chromosome 6:

ankylosing spondylitis, HLA-B collagenopathy, types II and XI Coeliac disease HLA-DQA1 and DQB1 Ehlers–Danlos syndrome, classical, hypermobility, and Tenascin-X types Hashimoto's thyroiditis hemochromatosis Hemochromatosis type 1 21-hydroxylase deficiency maple syrup urine disease methylmalonic acidemia Autosomal nonsyndromic deafness Narcolepsy North Carolina macular dystrophy otospondylomegaepiphyseal dysplasia Parkinson disease polycystic kidney disease porphyria porphyria cutanea tarda Rheumatoid arthritis, HLA-DR CIRS (Chronic Inflammatory Response Syndrome), Sick Building Syndrome, Mold Toxin Susceptibility / Poisoning, HLA-DR/DQ Spinocerebellar ataxia type 1, ATXN1 Stickler syndrome, COL11A2 Systemic lupus erythematosus Diabetes mellitus type 1, HLA-DR, DQA1 & DQB1 X-linked sideroblastic anemia Epilepsy Guillain–Barré syndrome Chordoma Hepatocellular carcinoma Schizophrenia

Cytogenetic band

+ G-bands of human chromosome 6 in resolution 850 bphsGenome Decoration Page, NCBI. Ideogram data for Homo sapience (850 bphs, Assembly GRCh38.p3). Last update 2014-06-03. Retrieved 2017-04-26. Chr. Arm"p": Short arm; "q": Long arm. BandFor cytogenetic banding nomenclature, see article locus. ISCNstartThese 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. ISCNstop Basepairstart Basepairstop Staingpos: 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. Density 6 p 25.3 0 118 gneg 6 p 25.2 118 207 gpos 25 6 p 25.1 207 355 gneg 6 p 24.3 355 548 gpos 50 6 p 24.2 548 592 gneg 6 p 24.1 592 740 gpos 25 6 p 23 740 844 gneg 6 p 22.3 844 1185 gpos 75 6 p 22.2 1185 1348 gneg 6 p 22.1 1348 1585 gpos 50 6 p 21.33 1585 1718 gneg 6 p 21.32 1718 1836 gpos 25 6 p 21.31 1836 2162 gneg 6 p 21.2 2162 2310 gpos 25 6 p 21.1 2310 2755 gneg 6 p 12.3 2755 3080 gpos 100 6 p 12.2 3080 3140 gneg 6 p 12.1 3140 3377 1 gpos 100 6 p 11.2 3377 3421 gneg 6 p 11.1 3421 3554 acen 6 q 11.1 3554 3658 acen 6 q 11.2 3658 3732 gneg 6 q 12 3732 4147 gpos 100 6 q 13 4147 4324 gneg 6 q 14.1 4324 4621 gpos 50 6 q 14.2 4621 4709 gneg 6 q 14.3 4709 4917 gpos 50 6 q 15 4917 5228 gneg 6 q 16.1 5228 5613 gpos 100 6 q 16.2 5613 5687 gneg 6 q 16.3 5687 5983 1 gpos 100 6 q 21 5983 6531 1 gneg 6 q 22.1 6531 6753 gpos 75 6 q 22.2 6753 6872 gneg 6 q 22.31 6872 7168 gpos 100 6 q 22.32 7168 7345 gneg 6 q 22.33 7345 7642 gpos 75 6 q 23.1 7642 7923 1 gneg 6 q 23.2 7923 8145 gpos 50 6 q 23.3 8145 8352 gneg 6 q 24.1 8352 8560 gpos 75 6 q 24.2 8560 8708 gneg 6 q 24.3 8708 8886 gpos 75 6 q 25.1 8886 9078 gneg 6 q 25.2 9078 9241 gpos 50 6 q 25.3 9241 9596 gneg 6 q 26 9596 9774 gpos 50 6 q 27 9774 10100 gneg

References

Notes Some text in this article was taken from http://ghr.nlm.nih.gov/chromosome=6 (public domain) Further reading

External links

"Chromosome 6 Research Project". Parent-driven research for genotype-phenotype studies on chromosome 6 disorders. Retrieved 2017-06-17