Chromosome 7 (human)

Chromosome 7 (human)
Human chromosome 7 pair after G-banding. One is from mother, one is from father.
Chromosome 7 pair in human male karyogram.
Features
Length (bp)	159,345,973 bp
Number of genes	2,146
Type	Autosome
Centromere position	Submetacentric
Identifiers
RefSeq	NC_000007
GenBank	CM000669

Ideogram of human chromosome 7. Mbp means mega base pair. See locus for other notation.

Chromosome 7 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 7 spans about 159 million base pairs (the building material of DNA) and represents between 5 and 5.5 percent of the total DNA in cells.

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 7 is likely to contain between 1,000 and 1,400 genes. It also contains the Homeobox A gene cluster.

Diseases and disorders

The following diseases are some of those related to genes on chromosome 7:

• argininosuccinic aciduria
• cerebral cavernous malformation
• Charcot–Marie–Tooth disease, type 2D
• Charcot–Marie–Tooth disease, type 2F
• 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, arthrochalasia type VII
• Ehlers–Danlos syndrome, classical type
• 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
• nonsyndromic deafness, autosomal dominant
• nonsyndromic deafness, autosomal recessive
• osteogenesis imperfecta
• osteogenesis imperfecta, type I
• osteogenesis imperfecta, type III
• osteogenesis imperfecta, type II
• osteogenesis imperfecta, type IV
• p47-phox-deficient chronic granulomatous disease
• Pendred syndrome
• Romano–Ward syndrome
• Shwachman–Diamond syndrome
• Schizophrenia
• Silver-Russell syndrome
• Specific language impairment
• Tritanopia or tritanomaly color blindness
• Williams 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.

External links

• Chromosome 7 - NCBI Map Viewer