Chromosome 6 is one of the 23 pairs of

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

s in

human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

s. People normally have two copies of this chromosome. Chromosome 6 spans nearly 171 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 Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

) and represents between 5.5 and 6% of the total DNA in cells. It contains the

major histocompatibility complex The major histocompatibility complex (MHC) is a large Locus (genetics), locus on vertebrate DNA containing a set of closely linked polymorphic genes that code for Cell (biology), cell surface proteins essential for the adaptive immune system. The ...

, which contains over 100 genes related to the

immune response An immune response is a physiological reaction which occurs within an organism in the context of inflammation for the purpose of defending against exogenous factors. These include a wide variety of different toxins, viruses, intra- and extracellula ...

, and plays a vital role in

organ transplantation Organ transplantation is a medical procedure in which an organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be trans ...

The evolution of human centromere 6

The

centromere The centromere links a pair of sister chromatids together during cell division. This constricted region of chromosome connects the sister chromatids, creating a short arm (p) and a long arm (q) on the chromatids. During mitosis, spindle fiber ...

of chromosome 6 illustrates an interesting example of centromere evolution. It was known that in a

Catarrhini The parvorder Catarrhini (known commonly as catarrhine monkeys, Old World anthropoids, or Old World monkeys) consists of the Cercopithecoidea and apes (Hominoidea). In 1812, Geoffroy grouped those two groups together and established the name ...

ancestor the chromosome 6 centromere was situated near position 26 Mb of the modern human chromosome. In ''Macaca mulatta'', this old centromere went defunct and repositioned to a different chromosomal location. In the case of humans, the old centromere went defunct and a more recent form emerged near the modern position of human cen6 (size of 60 Mb). Such cases are known as Evolutionary New Centromeres (ENC). This assembly phenomenon of the human chromosome 6 gives researchers an opportunity to investigate the origin of the ENC on chromosome 6.

Genes

The

human leukocyte antigen The human leukocyte antigen (HLA) system is a complex of genes on chromosome 6 in humans that encode cell-surface proteins responsible for regulation of the immune system. The HLA system is also known as the human version of the major histo ...

lies on chromosome 6, with the exception of the gene for β2-microglobulin (which is located on

chromosome 15 Chromosome 15 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 15 spans about 99.7 million base pairs (the building material of DNA) and represents between 3% and 3.5% of the total DNA ...

), and encodes cell-surface

antigen In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. ...

-presenting proteins among other functions.

Number of genes

In 2003, the entirety of chromosome 6 was manually annotated for proteins, resulting in the identification of 1,557 genes, and 633 pseudogenes. The following are some of the newer gene count estimates. Because researchers use different approaches to genome annotation their predictions of the

number of genes In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: prote ...

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 functio ...

). 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 6.

p-arm

The following are some of the genes located on p-arm (short arm) of human chromosome 6:

q-arm

The following are some of the genes located on q-arm (long arm) of human chromosome 6:

Diseases and disorders

The following diseases are some of those related to genes on chromosome 6: *

ankylosing spondylitis Ankylosing spondylitis (AS) is a type of arthritis from the disease spectrum of axial spondyloarthritis. It is characterized by long-term inflammation of the joints of the spine, typically where the spine joins the pelvis. With AS, eye and bow ...

, HLA-B * collagenopathy, types II and XI *

Coeliac disease Coeliac disease (British English) or celiac disease (American English) is a long-term autoimmune disorder, primarily affecting the small intestine. Patients develop intolerance to gluten, which is present in foods such as wheat, rye, spelt ...

HLA-DQA1 & DQB1 * Ehlers-Danlos syndrome, classical, hypermobility, and Tenascin-X types *

Hashimoto's thyroiditis Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis, Hashimoto's disease and autoimmune thyroiditis, is an autoimmune disease in which the thyroid gland is gradually destroyed. Early on, symptoms may not be noticed. Over ti ...

hemochromatosis Iron overload is the abnormal and increased accumulation of total iron in the body, leading to organ damage. The primary mechanism of organ damage is oxidative stress, as elevated intracellular iron levels increase free radical formation via the ...

* Hemochromatosis type 1 * 21-hydroxylase deficiency *

maple syrup urine disease Maple syrup urine disease (MSUD) is a rare, inherited metabolic disorder that affects the body's ability to metabolize amino acids due to a deficiency in the activity of the branched-chain alpha-ketoacid dehydrogenase (BCKAD) complex. It parti ...

* methylmalonic acidemia * Autosomal nonsyndromic deafness * North Carolina macular dystrophy * otospondylomegaepiphyseal dysplasia * Parkinson disease *

polycystic kidney disease Polycystic kidney disease (PKD or PCKD, also known as polycystic kidney syndrome) is a genetic disorder in which the renal tubules become structurally abnormal, resulting in the development and growth of multiple cysts within the kidney. These ...

porphyria Porphyria ( or ) is a group of disorders in which substances called porphyrins build up in the body, adversely affecting the skin or nervous system. The types that affect the nervous system are also known as Porphyria#Acute porphyrias, acute p ...

porphyria cutanea tarda Porphyria cutanea tarda (PCT) is a type of longterm porphyria characterised by fragile skin and sore blisters in areas of skin that receive higher levels of exposure to sunlight, such as the face and backs of the hands. These blisters burst easily ...

Rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects synovial joint, joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and h ...

, HLA-DR * CIRS (Chronic Inflammatory Response Syndrome ), Sick Building Syndrome, Mold Toxin Susceptibility / Poisoning, HLA-DR/DQ * Spinocerebellar ataxia type 1, ATXN1 * Stickler syndrome, COL11A2 *

Systemic lupus erythematosus Lupus, formally called systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common ...

Diabetes mellitus type 1 Type 1 diabetes (T1D), formerly known as juvenile diabetes, is an autoimmune disease that occurs when the body's immune system destroys pancreatic cells (beta cells). In healthy persons, beta cells produce insulin. Insulin is a hormone required ...

, HLA-DR, DQA1 & DQB1 * X-linked sideroblastic anemia *

Epilepsy Epilepsy is a group of Non-communicable disease, non-communicable Neurological disorder, neurological disorders characterized by a tendency for recurrent, unprovoked Seizure, seizures. A seizure is a sudden burst of abnormal electrical activit ...

* Guillain Barre Syndrome *

Chordoma Chordoma is a rare slow-growing neoplasm (cancer) that arises from cellular remnants of the notochord in the bones of the skull base and spine. The evidence for the notochordal origin of chordoma is the location of the tumors (along the neuraxis ...

Hepatocellular carcinoma Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults and is currently the most common cause of death in people with cirrhosis. HCC is the third leading cause of cancer-related deaths worldwide. HCC most common ...

Schizophrenia Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...

Cytogenetic band

References

;Notes *''Some text in this article was taken from http://ghr.nlm.nih.gov/chromosome=6 (public domain)''

External links

* * *
Chromosome 6 Research Project"
''Parent-driven research for genotype-phenotype studies on chromosome 6 disorders.'' Retrieved 2017-06-17 {{DEFAULTSORT:Chromosome 06 (Human) Chromosomes (human) *