Humans normally have 46 chromosomes in each cell, divided into 23 pairs. Two copies of chromosome 5, one inherited from each parent, form one of the pairs. Chromosome 5 comprises about 181 million DNA building blocks (base pairs) and makes up nearly 6% of all DNA in cells.
Identifying genes on each chromosome is an active area of genetic research. Because researchers use different approaches to predicting the number of genes on each chromosome, the estimated number of genes varies. Chromosome 5 probably contains about 900 genes that provide instructions for making proteins. These proteins serve a variety of different functions in the body.
Health conditions related to chromosomal alterations
The following chromosomal states are associated with changes in the structure or copy number of chromosome 5.
Deletion of a region of DNA from the long arm (q) of chromosome 5 is involved in a condition called 5q minus (5q) syndrome. This deletion occurs in immature blood cells throughout a person's lifetime and affects one copy of chromosome 5 in each cell. 5q syndrome is a form of bone marrow disease called myelodysplastic syndrome (MDS), in which immature blood cells fail to develop normally. People with 5q syndrome often have a lack of red blood cells (anemia) and abnormalities in blood cells called megakaryocytes, which make platelets that help the blood to clot. Affected people are also at increased risk of developing a fast-growing blood cancer known as acute myelogenous leukemia (AML).
Most people with 5q syndrome lack a DNA sequence of about 1.5 million base pairs, also written as 1.5 megabases (Mb). This region of DNA contains 40 genes. Research suggests that the loss of a copy of several genes in this region contributes to the characteristics of 5q syndrome. In particular, the loss ofRPS14gene leads to problems with red blood cell development and loss of red blood cells characteristic of 5q syndromeMIR145ÖMIR146Acontributes to megakaryocyte abnormalities. Scientists are still determining how the loss of other genes in the deleted region might be involved in the features of 5q syndrome and the development of AML.
More about this health condition
5q31.3 microdeletion syndrome
5q31.3 microdeletion syndrome is caused by a chromosomal abnormality in which a small portion of chromosome 5 in each cell is deleted. This rare disorder is characterized by severe delay in speech and gait development, poor muscle tone (hypotension), breathing problems, seizures, and distinctive facial features. The deletion occurs on the long (q) arm of the chromosome at a position designated q31.3. The size of the deletion can range from several thousand to several million DNA building blocks (base pairs). The deleted region usually contains at least three genes. The loss of one of these genesPURAIt is believed to lead to most of the features of the disease.
The protein made from itPURAThe gene called Pur-alpha (Purα) is particularly important for normal brain development. Purα helps direct the growth and division of nerve cells (neurons). It may also be involved in the formation or maturation of myelin, the protective substance that coats nerves and promotes the efficient transmission of nerve impulses. Loss of a copy ofPURAThe gene is thought to disrupt normal brain development and affect how neurons function, leading to developmental delays, hypotension, seizures, and other neurological problems in people with 5q31.3 microdeletion syndrome.
Some studies suggest that the loss of another nearby gene on chromosome 5, calledNRG2, increases the severity of signs and symptoms. It is not clear how the loss of other genes in the deleted region contributes to the development of the 5q31.3 microdeletion syndrome.
More about this health condition
Cri du chat (crying cat) syndrome is caused by a deletion of the end of the short arm (p) of chromosome 5. This chromosomal change is written as 5p- (minus 5p). The signs and symptoms of cri du chat syndrome are likely related to the loss of several genes in this region. Researchers are working to understand how the loss of these genes leads to the characteristics of the disorder. They found that in people with cri du chat syndrome, larger deletions tend to cause more severe intellectual disability and developmental delay than smaller deletions. The researchers also defined regions on the short arm of chromosome 5 that are associated with specific features of cri du chat syndrome. A specific region, labeled 5p15.3, is associated with a cat's cry, and a nearby region, labeled 5p15.2, is associated with intellectual disability, small head size (microcephaly), and distinctive facial features.
More about this health condition
Chronic eosinophilic leukemia associated with PDGFRB
Translocations involving chromosome 5 are involved in a type of cancer of blood cells called cancer.PDGFRB- Associated chronic eosinophilic leukemia. This condition is characterized by an increase in the number of eosinophils, a type of white blood cell. The most common translocation that causes this condition is the fusion of part of thePDGFRBChromosome 5 gene with part ofETV6Chromosome 12 gene written as t(5;12)(q31-33;p13). translocations that mergePDGFRBA gene with one of over 20 other genes was also found to be the cause.PDGFRBassociated with chronic eosinophilic leukemia, but these other genetic changes are relatively uncommon. These translocations are acquired throughout a person's lifetime and are present only in cancer cells. This type of genetic alteration, called a somatic mutation, is not inherited.
The protein made from itETV6-PDGFRBThe fusion gene, called ETV6/PDGFRβ, works differently than proteins normally made from individual genes. The ETV6 protein normally turns off (suppresses) gene activity, and the PDGFRβ protein plays a role in activating (activating) signaling pathways. The ETV6/PDGFRβ protein is always activated, activating signaling pathways and gene activity. if thatETV6-PDGFRBMutation of the fusion gene occurs in cells that become blood cells, the growth of eosinophils (and occasionally other white blood cells such as neutrophils and mast cells) is poorly controlled, leading to thisPDGFRB- Associated chronic eosinophilic leukemia. It is unclear why eosinophils are preferentially affected by this genetic alteration.
More about this health condition
In some cases, abnormalities on chromosome 5 have been associated with periventricular heterotopia, a disorder characterized by abnormal accumulations of neurons around fluid-filled cavities (ventricles) near the center of the brain. In each case, the affected person had extra genetic material caused by an abnormal duplication of part of that chromosome. It is not known how this duplicated genetic material leads to the signs and symptoms of periventricular heterotopia.
More about this health condition
Other chromosomal conditions
Other changes in the number or structure of chromosome 5 can cause a variety of effects, including delayed growth and development, distinctive facial features, birth defects, and other health problems. Changes on chromosome 5 include an extra segment of the short (p) or long (q) arm of the chromosome in each cell (partial trisomy 5p or 5q), a missing segment of the long arm of the chromosome in each cell (partial monosomy). 5q) and a circular structure called a ring chromosome 5. Ring chromosomes are formed when a chromosome splits in two places and the ends of the chromosome's arms fuse into a circular structure.
Other types of cancer
Deletions on the long arm (q) of chromosome 5 are common in AML and MDS. While deletions on a specific segment of chromosome 5 are associated with a form of MDS called 5q minus syndrome (described above), other deletions are associated with other forms of these blood disorders. These changes are mainly somatic, which means they are acquired throughout life and are present only in tumor cells.
Studies suggest that some genes on chromosome 5 play key roles in cell growth and division. When chromosome segments are deleted, as in some cases of AML and MDS, these important genes are missing. Without these genes, cells can grow and divide very quickly and out of control. Researchers are working to identify the specific genes on chromosome 5 that are linked to AML and MDS.
Additional information and resources
Additional Resources from the NIH
Scientific articles on PubMed
- Arefi M, Garcia JL, Penarrubia MJ, Queizan JA, Hermosin L, Lopez-Corral L, Megido M, Giraldo P, de las Heras N, Vanegas RJ, Gutierrez NC, Hernandez-Rivas JM. Frequency and clinical features of myeloproliferative neoplasms exibing PDGFRB rearrangement. Eur J Haematol. Jul 2012;89(1):37-41. doi:10.1111/j.1600-0609.2012.01799.x.PubMed Citation
- Cornish K, Bramble D. Cri du chat syndrome: genotype-phenotype correlations and recommendations for clinical management. Dev Med Child Neurol. July 2002; 44(7): 494-7. doi: 10.1017/s0012162201002419. No summary available.PubMed Citation
- Cross NC, Reiter A. Fibroblast growth factor receptor and platelet growth factor receptor abnormalities in eosinophilic myeloproliferative disorders. Hematol Law. 2008;119(4):199-206. doi: 10.1159/000140631. Epub 2008 June 20th.PubMed Citation
- [PubMed] Eisenmann KM, Dykema KJ, Matheson SF, Kent NF, DeWard AD, West RA, Tibes R, Furge KA, Alberts AS. 5q myelodysplastic syndromes: direct tumor suppression network of genes on chromosome 5q that recognize actin dynamics. oncogene. October 1, 2009; 28(39):3429-41. doi: 10.1038/onc.2009.207. Epub July 13, 2009.PubMed Citation
- Ensemble human map visualization
- Giagounidis A, Mufti GJ, Fenaux P, Germing U, List A, MacBeth KJ. Lenalidomide is a disease-modifying agent in patients with del(5q) myelodysplastic syndromes: linking mechanism of action to clinical outcomes. Ana Hematol. 2014 January;93(1):1-11. doi: 10.1007/s00277-013-1863-5. Epub September 10, 2013.PubMed CitationÖFree article at PubMed Central
- Hunt D, Leventer RJ, Simons C, Taft R, Swoboda KJ, Gawne-Cain M; DDD study; Magee AC, Turnpenny PD, Baralle D. Whole exome sequencing in familial triads reveals de novo mutations in PURA as a cause of severe neurodevelopmental delays and learning disabilities. J. Med. Genet. 2014 Dec;51(12):806-13. doi:10.1136/jmedgenet-2014-102798. Epub October 23, 2014.PubMed CitationÖFree article at PubMed Central
- Kumar MS, Narla A, Nonami A, Mullally A, Dimitrova N, Ball B, McAuley JR, Poveromo L, Kutok JL, Galili N, Raza A, Attar E, Gilliland DG, Jacks T, Ebert BL. Loss of coordinates of a microRNA and a protein-coding gene cooperate in the pathogenesis of 5q syndrome. Blood. October 27, 2011; 118(17): 4666-73. doi:10.1182/sangue-2010-12-324715. Epub 2011 August 26th.PubMed CitationÖFree article at PubMed Central
- Lalani SR, Zhang J, Schaaf CP, Brown CW, Magoulas P, Tsai AC, El-Gharbawy A, Wierenga KJ, Bartholomew D, Fong CT, Barbaro-Dieber T, Kukolich MK, Burrage LC, Austin E, Keller K, Pastore M, Fernandez F, Lotze T, Wilfong A, Purcarin G, ZhuW, Craigen WJ, McGuire M, Jain M, Cooney E, Azamian M, Bainbridge MN, Muzny DM, Boerwinkle E, Person RE, Niu Z, Eng CM, Lupski JR , Gibbs RA , Beaudet AL , Yang Y , Wang MC , Xia F. Soldier J Hum Genet . 6. November 2014;95(5):579-83. doi: 10.1016/j.ajhg.2014.09.014. Epub 2014 16. October.PubMed CitationÖFree article at PubMed Central
- PC Mainardi, C Perfumo, A Cali, G Coucourde, G Pastore, S Cavani, F Zara, J Overhauser, M Pierluigi, FD Bricarelli. Clinical and molecular characterization of 80 patients with 5p deletion: genotype-phenotype correlation. J. Med. Genet. 2001 Mar;38(3):151-8. doi: 10.1136/jmg.38.3.151.PubMed CitationÖFree article at PubMed Central
- Schafer IA, Robin NH, Posch JJ, Clark BA, Izumo S, Schwartz S. Distal 5q deletion syndrome: phenotypic correlations. I'm J Med Genet. September 15, 2001; 103(1): 63-8. doi:10.1002/ajmg.1513.PubMed Citation
- Schmutz J, Martin J, Terry A, Couronne O, Grimwood J, Lowry S, Gordon LA, Scott D, Xie G, Huang W, Hellsten U, Tran-Gyamfi M, She X, Prabhakar S, Aerts A, Altherr M, Bajorek E , Black S , Branscomb E , Caoile C , Challacombe JF , Chan YM , Denys M , Detter JC , Escobar J , Flowers D , Fotopulos D , Glavina T , Gomez M , Gonzales E , Goodstein D , Grigoriev I , Groza M , N. Hammon , T. Hawkins , L. Haydu , S. Israni , J. Jett , K. Kadner , H. Kimball , A. Kobayashi , F. Lopez , Y. Lou , D. Martinez , and C. Medina . Morgan, R. Nandkeshwar, JP Noonan, S. Pitluck, P. Predki, J. Priester, L. Ramirez, J. Retterer, A. Rodriguez, S. Rogers, A. Salamov, A. Salazar, N. Thayer , Tice H, Tsai M, Ustaszewska, N VO, Wheeler J, Wu K, Yang J, Dickson M, Cheng JF, Eichler EE, Olsen A, Pennacchio LA, Rokhsar DS, Richardson P, LucasSM, Myers RM, Rubin EM. A DNA Sequencing and Comparative Analysis of Human Chromosome 5. Nature. September 16, 2004; 431(7006):268–74. doi: 10.1038/nature02919.PubMed Citation
- Shimojima K, Isidor B, Le Caignec C, Kondo A, Sakata S, Ohno K, Yamamoto T. A novel 5q31.3 microdeletion syndrome characterized by severe developmental delays, distinctive facial features, and delayed myelination. Am J Med Genet A.2011 Apr;155A(4):732-6. doi: 10.1002/ajmg.a.33891. Epub Mar 15, 2011. Errata In: Am J Med Genet A Nov 2011; 155A(11):2903.PubMed Citation
- Siddiqi R, Gilbert F. Chromosome 5. Genet Test. Summer 2003;7(2):169-87. doi:10.1089/109065703322146902. No summary available.PubMed Citation
- UCSC Genombrowser: ace statistics
- Wu Q, Niebuhr E, Yang H, Hansen L. Determination of the "critical region" of cri du chat syndrome and analysis of candidate genes by quantitative PCR. Eur J Hum Genet. April 2005; 13(4):475-85. doi:10.1038/sj.ejhg.5201345.PubMed Citation
- Zhang X, Snijders A, Segraves R, Zhang X, Niebuhr A, Albertson D, Yang H, GrayJ, Niebuhr E, Bolund L, Pinkel D Matrix. Eu so J Hum Genet. February 2005; 76(2):312-26. doi: 10.1086/427762. epub2005 January 4PubMed CitationÖFree article at PubMed Central