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.

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. 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:
 * EDN3: endothelin 3
 * 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)
 * AHCY: S-adenosylhomocysteine hydrolase
 * ARFGEF2: ADP-ribosylation factor guanine nucleotide-exchange factor 2 (brefeldin A-inhibited)
 * GSS: glutathione synthetase
 * SALL4: sal-like 4 (Drosophila)
 * VAPB: VAMP (vesicle-associated membrane protein)-associated protein B and C
 * BMP2: Bone Morphogenetic Protein 2 (osteoblast differentiation)
 * GNAS1: Gs alpha subunit (membrane G-protein)

Diseases & disorders
The following diseases are some of those related to genes on chromosome 20:
 * Arterial tortuosity syndrome
 * Adenosine deaminase deficiency
 * Alagille syndrome
 * Celiac disease
 * Galactosialidosis - CTSA
 * Maturity onset diabetes of the young type 1
 * Pantothenate kinase-associated neurodegeneration
 * Transmissible spongiform encephalopathy (prion diseases)
 * Waardenburg syndrome