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, culture, ...
s. People normally have two copies of this chromosome. Chromosome 12 spans about 133 million
base pair
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...
s (the building material of
DNA) and represents between 4 and 4.5 percent of the total DNA in
cells.
Chromosome 12 contains the
Homeobox
A homeobox is a DNA sequence, around 180 base pairs long, that regulates large-scale anatomical features in the early stages of embryonic development. For instance, mutations in a homeobox may change large-scale anatomical features of the full- ...
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
DNA annotation or genome annotation is the process of identifying the locations of genes and all of the coding regions in a genome and determining what those genes do. An annotation (irrespective of the context) is a note added by way of explanati ...
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
In computational biology, gene prediction or gene finding refers to the process of identifying the regions of genomic DNA that encode genes. This includes protein-coding genes as well as RNA genes, but may also include prediction of other functiona ...
). 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:
*
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 ...
*
collagenopathy, types II and XI
The type II and XI collagenopathies are a group of disorders that affect connective tissue, the tissue that supports the body's joints and organs. These disorders are caused by defects in type II or type XI collagen. Collagens are complex molecul ...
*
cornea plana 2
Cornea plana 2 (CNA2) is a congenital disorder that causes the cornea to flatten and the angle between the sclera and cornea to shrink. This could result in the early development of arcus lipoides, hazy corneal limbus, and hyperopia. There is evid ...
*
episodic ataxia
Episodic ataxia (EA) is an autosomal dominant disorder characterized by sporadic bouts of ataxia (severe discoordination) with or without myokymia (continuous muscle movement). There are seven types recognized but the majority are due to two recog ...
*
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, ...
*
ichthyosis bullosa of Siemens
Ichthyosis bullosa of Siemens is a type of familial, autosomal dominant ichthyosis, a rare skin disorder.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . It is also known as bullous congenital ...
*
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
Kabuki syndrome (also previously known as Kabuki-makeup syndrome (KMS) or Niikawa–Kuroki syndrome) is a congenital disorder of genetic origin. It affects multiple parts of the body, with varying symptoms and severity, although the most common is ...
*
maturity onset diabetes of the young
Maturity-onset diabetes of the young (MODY) refers to any of several hereditary forms of diabetes mellitus caused by mutations in an autosomal dominant gene disrupting insulin production. MODY is often referred to as monogenic diabetes to disting ...
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 affec ...
*
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 followi ...
*
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 Parkinson may refer to:
*Parkinson (surname)
* ''Parkinson'' (TV series), British chat show, presented by Sir Michael Parkinson
*Parkinson, Queensland, suburb of Brisbane, Australia
*The Parkinsons (fl. early 20th century), American father-and-son ...
*
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 cell division, cells are dividing (mei ...
12p)
*
phenylketonuria
Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine. Untreated PKU can lead to intellectual disability, seizures, behavioral problems, and mental disorders. It may also resu ...
*
spondyloepimetaphyseal dysplasia, Strudwick type
*
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 ...
*
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)
*
Stuttering
Stuttering, also known as stammering, is a speech disorder in which the flow of speech is disrupted by involuntary repetitions and prolongations of sounds, syllables, words, or phrases as well as involuntary silent pauses or blocks in which the ...
*
Triose Phosphate Isomerase deficiency
Triosephosphate isomerase deficiency is a rare autosomal recessive metabolic disorder which was initially described in 1965.
It is a unique glycolytic enzymopathy that is characterized by chronic haemolytic anaemia, cardiomyopathy, susceptibil ...
*
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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