Chromosome 20 (human)
Encyclopedia
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
s in human
Human
Humans are the only living species in the Homo genus...
s. People normally have two copies of this chromosome. Chromosome 20 spans around 63 million base pair
Base pair
In molecular biology and genetics, the linking between two nitrogenous bases on opposite complementary DNA or certain types of RNA strands that are connected via hydrogen bonds is called a base pair...
s (the building material of DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
) and represents between 2 and 2.5 percent of the total DNA in cells
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
. Chromosome 20 was fully sequenced in 2001 and contained 59,187,298 base pairs representing 99.4% of the euchromatic DNA.
Identifying gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
s on each chromosome is an active area of genetic research. Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. Chromosome 20 contains over 900 genes. New discoveries have recently linked this chromosome to the increasing susceptibility to male-pattern baldness.
Genes
The following are some of the genes located on chromosome 20:- AHCYAdenosylhomocysteinaseAdenosylhomocysteinase is an enzyme that converts S-adenosylhomocysteine to homocysteine and adenosine....
: S-adenosylhomocysteine hydrolase - ARFGEF2ARFGEF2Brefeldin A-inhibited guanine nucleotide-exchange protein 2 is a protein that in humans is encoded by the ARFGEF2 gene.-Interactions:ARFGEF2 has been shown to interact with ARFGEF1, PRKAR1A and PRKAR2A.-Further reading:...
: ADP-ribosylation factor guanine nucleotide-exchange factor 2 (brefeldin A-inhibited) - BMP2Bone morphogenetic protein 2Bone morphogenetic protein 2 or BMP-2 belongs to the TGF-β superfamily of proteins.-Function:BMP-2 like other bone morphogenetic proteins, plays an important role in the development of bone and cartilage. It is involved in the hedgehog pathway, TGF beta signaling pathway, and in cytokine-cytokine...
: Bone Morphogenetic Protein 2 (osteoblast differentiation) - DNAJC5DNAJC5DnaJ homolog subfamily C member 5, also known as cysteine string protein or CSP is a protein, that in humans encoded by the DNAJC5 gene. It was first described in 1990.- Gene :...
: Cysteine string protein - EDN3: endothelin 3
- GSSGlutathione synthetaseGlutathione synthetase is the second enzyme in the glutathione biosynthesis pathway. It catalyses the condensation of gamma-glutamylcysteine and glycine, to form glutathione.In eukaryotes, this is a homodimeric enzyme...
: glutathione synthetase - GNAS1Gs alpha subunitThe Gs alpha subunit is a heterotrimeric G protein subunit that activates the cAMP-dependent pathway by activating adenylate cyclase.-Receptors:The G protein-coupled receptors that couple to this kind of G-protein include:...
: Gs alpha subunit (membrane G-protein) - JAG1JAG1JAG1 is a protein associated with Alagille syndrome. JAG1 has also been designated as CD339 .-External links:* *...
: jagged 1 (Alagille syndrome) - PANK2: pantothenate kinase 2 (Hallervorden-Spatz syndrome)
- PRNPPRNPMajor prion protein also known as CD230 is a protein that in humans is encoded by the PRNP gene...
: prion protein (p27-30) (Creutzfeld-Jakob disease, Gerstmann-Strausler-Scheinker syndrome, fatal familial insomnia) - tTGTissue transglutaminaseTissue transglutaminase is an enzyme of the transglutaminase family. Like other transglutaminases, it crosslinks proteins between an ε-amino group of a lysine residue and a γ-carboxamide group of glutamine residue, creating an inter- or intramolecular bond that is highly resistant to proteolysis...
: tissue transglutaminase (Celiac disease) - SALL4SALL4Sal-like protein 4 is a protein that in humans is encoded by the SALL4 gene.It can be associated with Duane-radial ray syndrome.-External links:*-Further reading:...
: sal-like 4 (Drosophila) - VAPBVAPBVesicle-associated membrane protein-associated protein B/C is a protein that in humans is encoded by the VAPB gene.-Further reading:...
: VAMP (vesicle-associated membrane protein)-associated protein B and C
Diseases & disorders
The following diseases are some of those related to genes on chromosome 20:- Arterial tortuosity syndromeArterial tortuosity syndromeArterial tortuosity syndrome is a rare congenital connective tissue condition disorder characterized by elongation and generalized tortuosity of the major arteries including the aorta...
- Adenosine deaminase deficiencyAdenosine deaminase deficiencyAdenosine deaminase deficiency, also called ADA deficiency or ADA-SCID, is an autosomal recessive metabolic disorder that causes immunodeficiency. It occurs in fewer than one in 100,000 live births worldwide....
- Alagille syndromeAlagille syndromeAlagille syndrome is a genetic disorder that affects the liver, heart, kidney, and other systems of the body. Problems associated with the disorder generally become evident in infancy or early childhood...
- Celiac disease
- GalactosialidosisGalactosialidosisGalactosialidosis is a lysosomal storage disease.It is associated with cathepsin A.-External links:*...
- CTSACathepsin ACathepsin A is an enzyme which is classified both as a cathepsin and a carboxypeptidase. In humans, it is encoded by the CTSA gene.- Function :... - Maturity onset diabetes of the youngMaturity onset diabetes of the youngMaturity onset diabetes of the young refers to any of several hereditary forms of diabetes caused by mutations in an autosomal dominant gene disrupting insulin production...
type 1 - Neuronal ceroid lipofuscinosisNeuronal Ceroid LipofuscinosisNeuronal Ceroid Lipofuscinoses is the general name for a family of at least eight genetically separate neurodegenerative disorders that result from excessive accumulation of lipopigments in the body's tissues. These lipopigments are made up of fats and proteins...
- Pantothenate kinase-associated neurodegenerationPantothenate kinase-associated neurodegenerationPantothenate kinase-associated neurodegeneration , also known as neurodegeneration with brain iron accumulation 1 and formerly called Hallervorden-Spatz syndrome Pantothenate kinase-associated neurodegeneration (PKAN), also known as neurodegeneration with brain iron accumulation 1 (NBIA1) and...
- Transmissible spongiform encephalopathyTransmissible spongiform encephalopathyTransmissible spongiform encephalopathies , also known as prion diseases, are a group of progressive conditions that affect the brain and nervous system of many animals, including humans. According to the most widespread hypothesis they are transmitted by prions, though some other data suggest an...
(prion diseases) - Waardenburg syndromeWaardenburg syndromeWaardenburg syndrome Waardenburg syndrome Waardenburg syndrome (also Waardenburg Shah Syndrome, Waardenburg-Klein syndrome, Mende's syndrome II, Van der Hoeve-Halbertsma-Waardenburg syndrome, Ptosis-Epicanthus syndrome, Van der Hoeve-Halbertsma-Gualdi syndrome, Waardenburg type Pierpont,[5] Van...
External links
- Human Chromosome 20 Map Viewer — on NCBI