Chromosome 7 is one of the 23 pairs of chromosomes in humans, who normally have two copies of this chromosome. Chromosome 7 spans about 160 millionWhat is chromosome 7, "Genetics Home Reference" of U.S. National Library of Medicine. April 2008. [2014-05-14]. base pairs (the building material of DNA) and represents between 5 and 5.5 percent of the total DNA in cells.

Genes Number of genes The following are some of the gene count estimates of human chromosome 7. 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 862 — — 2016-09-08 HGNC 870 245 703 2017-05-12 Ensembl 984 973 889 2017-03-29 UniProt 944 — — 2018-02-28 NCBI 948 905 933 2017-05-19

Partial gene list

The following is a partial list of genes on human chromosome 7. 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 7:

7p22.1 microduplication syndrome argininosuccinic aciduria cerebral cavernous malformation Charcot–Marie–Tooth disease Cholestasis, progressive familial intrahepatic 3 Citrullinemia, type II, adult-onset, congenital bilateral absence of vas deferens cystic fibrosis<ref name="Hillier 2003"></bn></ref> Developmental verbal dyspraxia distal spinal muscular atrophy, type V Ehlers–Danlos syndrome hemochromatosis, type 3 Hereditary nonpolyposis colorectal cancer HNPCC4 Lissencephaly syndrome, norman-roberts type Marfan syndrome maple syrup urine disease maturity onset diabetes of the young type 3 mucopolysaccharidosis type VII or Sly syndrome Muscular dystrophy, limb-girdle, type 1D myelodysplastic syndrome Myotonia congenita nonsyndromic deafness O'Donnell-Luria–Rodan syndrome osteogenesis imperfecta p47-phox-deficient chronic granulomatous disease Pectus excavatum Pendred syndrome Romano–Ward syndrome Shwachman–Diamond syndrome Schizophrenia Silver-Russell syndrome Specific language impairment Tritanopia or tritanomaly color blindness Williams syndrome Zellweger syndrome

Chromosomal disorders The following conditions are caused by changes in the structure or number of copies of chromosome 7: Williams syndrome is caused by the deletion of genetic material from a portion of the long (q) arm of chromosome 7. The deleted region, which is located at position 11.23 (written as 7q11.23), is designated as the Williams syndrome critical region. This region includes more than 20 genes, and researchers believe that the characteristic features of Williams syndrome are probably related to the loss of multiple genes in this region.

While a few of the specific genes related to Williams syndrome have been identified, the relationship between most of the genes in the deleted region and the signs and symptoms of Williams syndrome is unknown. Other changes in the number or structure of chromosome 7 can cause delayed growth and development, mental disorder, characteristic facial features, skeletal abnormalities, delayed speech, and other medical problems. These changes include an extra copy of part of chromosome 7 in each cell (partial trisomy 7) or a missing segment of the chromosome in each cell (partial monosomy 7). In some cases, several DNA building blocks (nucleotides) are deleted or duplicated in part of chromosome 7. A circular structure called ring chromosome 7 is also possible. A ring chromosome occurs when both ends of a broken chromosome are reunited.

Cytogenetic band

+ G-bands of human chromosome 7 in resolution 850 bphs 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 7 p 22.3 0 227 gneg 7 p 22.2 227 397 gpos 25 7 p 22.1 397 610 gneg 7 p 21.3 610 908 gpos 100 7 p 21.2 908 965 gneg 7 p 21.1 965 1121 gpos 100 7 p 15.3 1121 1419 gneg 7 p 15.2 1419 1589 gpos 50 7 p 15.1 1589 1816 gneg 7 p 14.3 1816 1986 gpos 75 7 p 14.2 1986 2043 gneg 7 p 14.1 2043 2327 gpos 75 7 p 13 2327 2639 gneg 7 p 12.3 2639 2838 gpos 75 7 p 12.2 2838 2909 gneg 7 p 12.1 2909 3093 gpos 75 7 p 11.2 3093 3306 gneg 7 p 11.1 3306 3448 acen 7 q 11.1 3448 3689 acen 7 q 11.21 3689 3973 gneg 7 q 11.22 3973 4171 gpos 50 7 q 11.23 4171 4597 gneg 7 q 21.11 4597 4994 gpos 100 7 q 21.12 4994 5108 gneg 7 q 21.13 5108 5292 gpos 75 7 q 21.2 5292 5406 gneg 7 q 21.3 5406 5661 gpos 75 7 q 22.1 5661 6129 gneg 7 q 22.2 6129 6300 gpos 50 7 q 22.3 6300 6470 gneg 7 q 31.1 6470 6683 gpos 75 7 q 31.2 6683 6867 gneg 7 q 31.31 6867 7094 gpos 75 7 q 31.32 7094 7208 gneg 7 q 31.33 7208 7364 gpos 75 7 q 32.1 7364 7449 gneg 7 q 32.2 7449 7576 gpos 25 7 q 32.3 7576 7803 gneg 7 q 33 7803 8031 gpos 50 7 q 34 8031 8371 gneg 7 q 35 8371 8612 gpos 75 7 q 36.1 8612 8910 gneg 7 q 36.2 8910 9080 gpos 25 7 q 36.3 9080 9350 gneg

In popular culture

Novels In the novel Performance Anomalies, researchers at Stanford University identify mutations in the long (q) arm of chromosome 7 as underlying the accelerated nervous system of the spy protagonist Cono, who receives the moniker Cono 7Q

References

Further reading

External links