Chromosome 12 is one of the 23 pairs of
chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...
s in
human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...
s. People normally have two copies of this chromosome. Chromosome 12 spans about 133 million
base pairs (the building material of
DNA) and represents between 4 and 4.5 percent of the total DNA in
cells.
Chromosome 12 contains the
Homeobox C gene cluster.
Genes
Number of genes
The following are some of the gene count estimates of human chromosome 12. Because researchers use different approaches to
genome annotation their predictions of the
number of genes
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
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.
Gene list
The following is a partial list of genes on human chromosome 12. 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 12:
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achondrogenesis type 2
Achondrogenesis, type 2 results in short arms and legs, a small chest with short ribs, and underdeveloped lungs at birth. Achondrogenesis, type 2 is a subtype of collagenopathy, types II and XI. This condition is also associated with a lack of bon ...
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collagenopathy, types II and XI
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cornea plana 2
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episodic ataxia
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hereditary hemorrhagic telangiectasia
Hereditary hemorrhagic telangiectasia (HHT), also known as Osler–Weber–Rendu disease and Osler–Weber–Rendu syndrome, is a rare autosomal dominant genetic disorder that leads to abnormal blood vessel formation in the skin, mucous membranes, ...
*
hypochondrogenesis
Hypochondrogenesis is a severe genetic disorder causing malformations of bone growth. The condition is characterized by a short body and limbs and abnormal bone formation in the spine and pelvis.
Hypochondrogenesis is a subtype of collagenopathy, ...
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ichthyosis bullosa of Siemens
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Kniest dysplasia
Kniest dysplasia is a rare form of dwarfism caused by a mutation in the ''COL2A1'' gene on chromosome 12. The ''COL2A1'' gene is responsible for producing type II collagen. The mutation of ''COL2A1'' gene leads to abnormal skeletal growth and pr ...
*
Kabuki syndrome
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maturity onset diabetes of the young type 3
*
methylmalonic acidemia
Methylmalonic acidemia, also called methylmalonic aciduria, is an autosomal recessive metabolic disorder that disrupts normal amino acid metabolism. It is a classical type of organic acidemia. The result of this condition is the inability to prope ...
*
narcolepsy
Narcolepsy is a long-term neurological disorder that involves a decreased ability to regulate sleep–wake cycles. Symptoms often include periods of excessive daytime sleepiness and brief involuntary sleep episodes. About 70% of those affect ...
*
nonsyndromic deafness
Nonsyndromic deafness is hearing loss that is not associated with other signs and symptoms. In contrast, syndromic deafness involves hearing loss that occurs with abnormalities in other parts of the body. Genetic changes are related to the follow ...
*
Noonan syndrome
Noonan syndrome (NS) is a genetic disorder that may present with mildly unusual facial features, short height, congenital heart disease, bleeding problems, and skeletal malformations. Facial features include widely spaced eyes, light-colored ...
*
Parkinson disease
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Pallister-Killian syndrome (
tetrasomy
A tetrasomy is a form of aneuploidy with the presence of four copies, instead of the normal two, of a particular chromosome.
Causes Full
Full tetrasomy of an individual occurs due to non-disjunction when the cells are dividing (meiosis I or II) ...
12p)
*
phenylketonuria
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spondyloepimetaphyseal dysplasia, Strudwick type
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spondyloepiphyseal dysplasia congenita
Spondyloepiphyseal dysplasia congenita (abbreviated to SED more often than SDC) is a rare disorder of bone growth that results in dwarfism, characteristic skeletal abnormalities, and occasionally problems with vision and hearing. The name of t ...
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spondyloperipheral dysplasia
Spondyloperipheral dysplasia is an autosomal dominant disorder of bone growth. The condition is characterized by flattened bones of the spine ( platyspondyly) and unusually short fingers and toes ( brachydactyly). Some affected individuals also ...
*
Stickler syndrome, (
COL2A1
Collagen, type II, alpha 1 (primary osteoarthritis, spondyloepiphyseal dysplasia, congenital), also known as COL2A1, is a human gene that provides instructions for the production of the pro-alpha1(II) chain of type II collagen.
Function
This ge ...
-related)
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Stuttering
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Triose Phosphate Isomerase deficiency
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tyrosinemia
Tyrosinemia or tyrosinaemia is an error of metabolism, usually inborn, in which the body cannot effectively break down the amino acid tyrosine. Symptoms of untreated tyrosinemia include liver and kidney disturbances. Without treatment, tyrosinemi ...
*
Von Willebrand Disease
Von Willebrand disease (VWD) is the most common hereditary blood-clotting disorder in humans. An acquired form can sometimes result from other medical conditions. It arises from a deficiency in the quality or quantity of von Willebrand factor ...
Cytogenetic band
References
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External links
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{{DEFAULTSORT:Chromosome 12 (Human)
Chromosomes (human)
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