Chromosome 7

Chromosome 7 is one of the 23 pairs of chromosomes in humans, who normally have two copies of this chromosome. Chromosome 7 spans about 160 million base pairs (the building material of DNA) and represents between 5 and 5.5 percent of the total DNA in cells.

Genes

Number of genes

The following are some of the gene count estimates of human chromosome 7. Because researchers use different approaches to genome annotation their predictions of the number of genes 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.

Partial gene list

The following is a partial list of genes on human chromosome 7. 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 7:

• 7p22.1 microduplication syndrome
• argininosuccinic aciduria
• cerebral cavernous malformation
• Charcot–Marie–Tooth disease
• Cholestasis, progressive familial intrahepatic 3
• Citrullinemia, type II, adult-onset,
• congenital bilateral absence of vas deferens
• cystic fibrosis
• Developmental verbal dyspraxia
• distal spinal muscular atrophy, type V
• Ehlers–Danlos syndrome
• hemochromatosis, type 3
• Hereditary nonpolyposis colorectal cancer HNPCC4
• Lissencephaly syndrome, norman-roberts type
• Marfan syndrome
• maple syrup urine disease
• maturity onset diabetes of the young type 3
• mucopolysaccharidosis type VII or Sly syndrome
• Muscular dystrophy, limb-girdle, type 1D
• myelodysplastic syndrome
• Myotonia congenita
• nonsyndromic deafness
• O'Donnell-Luria–Rodan syndrome
• osteogenesis imperfecta
• p47-phox-deficient chronic granulomatous disease
• Pectus excavatum
• Pendred syndrome
• Romano–Ward syndrome
• Shwachman–Diamond syndrome
• Schizophrenia
• Silver-Russell syndrome
• Specific language impairment
• Tritanopia or tritanomaly color blindness
• Williams syndrome
• Zellweger syndrome

Chromosomal disorders

The following conditions are caused by changes in the structure or number of copies of chromosome 7:

• Williams syndrome is caused by the deletion of genetic material from a portion of the long (q) arm of chromosome 7. The deleted region, which is located at position 11.23 (written as 7q11.23), is designated as the Williams syndrome critical region. This region includes more than 20 genes, and researchers believe that the characteristic features of Williams syndrome are probably related to the loss of multiple genes in this region.

While a few of the specific genes related to Williams syndrome have been identified, the relationship between most of the genes in the deleted region and the signs and symptoms of Williams syndrome is unknown.

• Other changes in the number or structure of chromosome 7 can cause delayed growth and development, mental disorder, characteristic facial features, skeletal abnormalities, delayed speech, and other medical problems. These changes include an extra copy of part of chromosome 7 in each cell (partial trisomy 7) or a missing segment of the chromosome in each cell (partial monosomy 7). In some cases, several DNA building blocks (nucleotides) are deleted or duplicated in part of chromosome 7. A circular structure called ring chromosome 7 is also possible. A ring chromosome occurs when both ends of a broken chromosome are reunited.

Cytogenetic band

In popular culture

Novels

In the novel Performance Anomalies, researchers at Stanford University identify mutations in the long (q) arm of chromosome 7 as underlying the accelerated nervous system of the spy protagonist Cono, who receives the moniker Cono 7Q

References

Further reading

External links