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 genome annotation their predictions of the number of genes on each chromosome varies. In January 2017, two estimates differed by 10%, with one estimate giving 2,774 genes, and the other estimate giving 2,500 genes.
Some of the genes found on human chromosome 7 are:
AGK: encoding enzyme mitochondrial acylglycerol kinase
AASS: encoding enzyme Alpha-aminoadipic semialdehyde synthase, mitochondrial
C7orf20: encoding protein UPF0363 protein C7orf20
C7orf43: encoding protein
EZH2: encoding enzyme histone-lysine N-methyltransferase for histone h3 lysine 27
INTS1: encoding protein Integrator complex subunit 1
KDM7A: encoding protein Lysine demethylase 7A
PVRIG: encoding protein Poliovirus receptor related immunoglobulin domain containing
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
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.
