Chromosome 5

Chromosome 5
Human chromosome 5 pair after G-banding. One is from mother, one is from father.
Chromosome 5 pair in human male karyogram.
Features
Length (bp)	182,045,439 bp (CHM13)
No. of genes	839 (CCDS)[1]
Type	Autosome
Centromere position	Submetacentric[2] (48.8 Mbp[3])
Complete gene lists
CCDS	Gene list
HGNC	Gene list
UniProt	Gene list
NCBI	Gene list
External map viewers
Ensembl	Chromosome 5
Entrez	Chromosome 5
NCBI	Chromosome 5
UCSC	Chromosome 5
Full DNA sequences
RefSeq	NC_000005 (FASTA)
GenBank	CM000667 (FASTA)

Chromosome 5 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 5 spans about 182 million base pairs (the building blocks of DNA) and represents almost 6% of the total DNA in cells. Chromosome 5 is the 5th largest human chromosome, yet has one of the lowest gene densities. This is partially explained by numerous gene-poor regions that display a remarkable degree of non-coding and syntenic conservation with non-mammalian vertebrates, suggesting they are functionally constrained.^[4]

Because chromosome 5 is responsible for many forms of growth and development (cell divisions) changes may cause cancers. One example would be acute myeloid leukemia (AML).^[5]

Genes

Number of genes

The following are some of the gene count estimates of human chromosome 5. 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.^[6]

Gene list

The following is a partial list of genes on human chromosome 5. For complete list, see the link in the infobox on the right.

Diseases and disorders

The following are some of the diseases related to genes located on chromosome 5:

• Achondrogenesis type 1B
• Atelosteogenesis, type II
• Bosch-Boonstra-Schaaf optic atrophy syndrome
• Charcot–Marie–Tooth disease, type 4
• Cockayne syndrome
• Cornelia de Lange syndrome
• Corneal dystrophy of Bowman layer
• Cri du chat
• Diastrophic dysplasia
• Ehlers-Danlos syndrome
• Familial adenomatous polyposis
• Granular corneal dystrophy type I
• Granular corneal dystrophy type II
• GM2-gangliosidosis, AB variant
• Homocystinuria
• 3-Methylcrotonyl-CoA carboxylase deficiency
• Myelodysplastic syndrome
• Netherton syndrome
• Nicotine dependency
• Parkinson's disease
• Primary carnitine deficiency
• Recessive multiple epiphyseal dysplasia
• Sandhoff disease
• Spinal muscular atrophy
• Sotos Syndrome
• Survival motor neuron spinal muscular atrophy
• Treacher Collins syndrome
• Tricho-hepato-enteric syndrome
• Usher syndrome

Chromosomal conditions

The following conditions are caused by changes in the structure or number of copies of chromosome 5:

• Cri-du-chat syndrome is caused by a deletion of the end of the short (p) arm of chromosome 5. This chromosomal change is written as 5p-. The signs and symptoms of cri-du-chat syndrome are probably related to the loss of multiple genes in this region. Researchers have not identified all of these genes or determined how their loss leads to the features of the disorder. They have discovered, however, that a larger deletion tends to result in more severe mental retardation and developmental delays in people with cri-du-chat syndrome.^[13][14][15]

Researchers have defined narrow regions of the short arm of chromosome 5 that are associated with particular features of cri-du-chat syndrome. A specific region designated 5p15.3 is associated with a cat-like cry, and a nearby region called 5p15.2 is associated with mental retardation, small head (microcephaly), and distinctive facial features.

• Familial Adenomatous Polyposis is caused by a deletion of the APC tumor suppressor gene on the long (q) arm of chromosome 5. This chromosomal change results in thousands of colonic polyps which gives the patient a 100% risk of colon cancer if total colectomy is not done.
• Chromosome 5q deletion syndrome is caused by the deletion of the q arm (long arm) of chromosome 5. This deletion has been linked to several blood related disorders including Myelodysplastic syndrome and Erythroblastopenia. This is a different condition than Cri-du-chat which was mentioned above.
• Other changes in the number or structure of chromosome 5 can have a variety of effects, including delayed growth and development, distinctive facial features, birth defects, and other medical problems. Changes to chromosome 5 include an extra segment of the short (p) or long (q) arm of the chromosome in each cell (partial trisomy 5p or 5q), a missing segment of the long arm of the chromosome in each cell (partial monosomy 5q), and a circular structure called ring chromosome 5. A ring chromosome occurs when both ends of a broken chromosome are reunited.

Cytogenetic band

G-banding ideograms of human chromosome 5

G-banding ideogram of human chromosome 5 in resolution 850 bphs. Band length in this diagram is proportional to base-pair length. This type of ideogram is generally used in genome browsers (e.g. Ensembl, UCSC Genome Browser).

G-banding patterns of human chromosome 5 in three different resolutions (400,^[16] 550^[17] and 850^[3]). Band length in this diagram is based on the ideograms from ISCN (2013).^[18] This type of ideogram represents actual relative band length observed under a microscope at the different moments during the mitotic process.^[19]

References

Further reading

External links

• National Institutes of Health. "Chromosome 5". Genetics Home Reference. http://ghr.nlm.nih.gov/chromosome=5. 
• "Chromosome 5". http://web.ornl.gov/sci/techresources/Human_Genome/posters/chromosome/chromo05.shtml. 

0.00 (0 votes) Original source: https://en.wikipedia.org/wiki/Chromosome 5. Read more