Chromosome 20 (human)

Chromosome 20 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 20 spans around 63 million base pairs (the building material of DNA) and represents between 2 and 2.5 percent of the total DNA in cells. Chromosome 20 was fully sequenced in 2001 and contained 59,187,298 base pairs representing 99.4% of the euchromatic DNA.^[1]

Identifying genes 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.^{[citation needed]} Chromosome 20 contains over 900 genes. New discoveries^[when?] have recently linked this chromosome to the increasing susceptibility to male-pattern baldness.^{[citation needed]}

Genes

The following are some of the genes located on chromosome 20:

• AHCY: S-adenosylhomocysteine hydrolase
• ARFGEF2: ADP-ribosylation factor guanine nucleotide-exchange factor 2 (brefeldin A-inhibited)
• BMP2: Bone Morphogenetic Protein 2 (osteoblast differentiation)
• DNAJC5: Cysteine string protein
• EDN3: endothelin 3
• GSS: glutathione synthetase
• GNAS1: Gs alpha subunit (membrane G-protein)
• JAG1: jagged 1 (Alagille syndrome)
• PANK2: pantothenate kinase 2 (Hallervorden-Spatz syndrome)
• PRNP: prion protein (p27-30) (Creutzfeld-Jakob disease, Gerstmann-Strausler-Scheinker syndrome, fatal familial insomnia)
• tTG: tissue transglutaminase (Celiac disease)
• SALL4: sal-like 4 (Drosophila)
• VAPB: 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:^[2]

• Arterial tortuosity syndrome
• Adenosine deaminase deficiency
• Alagille syndrome
• Celiac disease
• Galactosialidosis - CTSA
• Maturity onset diabetes of the young type 1
• Neuronal ceroid lipofuscinosis
• Pantothenate kinase-associated neurodegeneration
• Transmissible spongiform encephalopathy (prion diseases)
• Waardenburg syndrome

References

1. ^ Deloukas P, et al. (2001). "The DNA sequence and comparative analysis of human chromosome 20". Nature 414 (6866): 865–871. doi:10.1038/414865a. PMID 11780052. 
2. ^ Gilbert F (1997). "Disease genes and chromosomes: disease maps of the human genome". Genet Test 1 (3): 225–229. doi:10.1089/gte.1997.1.225. PMID 10464650. 

External links

• Human Chromosome 20 Map Viewer — on NCBI