Marker hromosom

Marker hromosom (mar) je mali fragment hromosoma koji se općenito ne može identificirati bez specijalizirane genomske analize, zbog veličine fragmenta.^[1] Značaj markera je promjenjiv jer zavisi od materijala koji se u njemu nalazi.^[2] Velika većina ovih markerskih hromosoma je manja od jednog od manjih ljudskih hromosoma, hromosoma 20, i po definiciji se nazivaju mali prekobrojni markerski hromosomi.^[3]

Markerski hromosomi se javljaju sporadično u oko 70% slučajeva, dok se ostatak nasljeđuje od roditelja. Oko 50% slučajeva uključuje mozaične, što utiče na težinu stanja. Učestalost je otprilike 3-4 na 10.000 ljudi i 1 od 300 osoba sa mentalnom retardacijom.^[2]

Markerski hromosomi se obično javljaju pored standardnih 46 hromosoma, što ih čini delimičnim trisomijama ili tetrasomijama prekobrojnih hromosoma.^[4] Marker može biti sastavljen od neaktivnog genetičkog materijala i imati malo ili nimalo efekta, ili može nositi aktivne gene i uzrokovati genetička stanja kao što je izo(12p), koji je povezan sa Pallister-Killianovim sindromom, i izo(18p), koji je povezan sa mentalnom retardacijom i sindromskim facijesom.^[5] Zapaženo je da hromosom 15 doprinosi velikom broju markerskih hromosoma, ali razlog nije utvrđen.^[1] Članak mali prekobrojni markerski hromosom (sSMC) sadrži primjere drugih [[urođena mana|urođenih mahana] ], sindroma i tumoria koji su povezani s različitim tipovima sSMC.

Reference[uredi | uredi izvor]

^ ^a ^b Thompson & Thompson Genetics in Medicine, Chapter 5, 57-74 https://www.clinicalkey.com/#!/content/book/3-s2.0-B9781437706963000054?scrollTo=%23hl0000654
^ ^a ^b Nelson Textbook of Pediatrics, Chapter 81, 604-627 https://www.clinicalkey.com/#!/content/book/3-s2.0-B9781455775668000818?scrollTo=%23hl0003126
^ Sun M, Zhang H, Li G, Guy CJ, Wang X, Lu X, Gong F, Lee J, Hassed S, Li S (September 2017). "Molecular characterization of 20 small supernumerary marker chromosome cases using array comparative genomic hybridization and fluorescence in situ hybridization". Scientific Reports. 7 (1): 10395. Bibcode:2017NatSR...710395S. doi:10.1038/s41598-017-10466-z. PMC 5583289. PMID 28871159.
^ Jafari-Ghahfarokhi H, Moradi-Chaleshtori M, Liehr T, Hashemzadeh-Chaleshtori M, Teimori H, Ghasemi-Dehkordi P (2015). "Small supernumerary marker chromosomes and their correlation with specific syndromes". Advanced Biomedical Research. 4: 140. doi:10.4103/2277-9175.161542. PMC 4544121. PMID 26322288.
^ Baldwin, Erin L.; May, Lorraine F.; Justice, April N.; Martin, Christa L.; Ledbetter, David H. (8 February 2008). "Mechanisms and Consequences of Small Supernumerary Marker Chromosomes: From Barbara McClintock to Modern Genetic-Counseling Issues". American Journal of Human Genetics. 82 (2): 398–410. doi:10.1016/j.ajhg.2007.10.013. PMC 2427313. PMID 18252220.

Vanjski linkovi[uredi | uredi izvor]

https://web.archive.org/web/20060926021351/http://www.chromodisorder.org/sytrix/card_list.php3?dbid=63&id=365 An International System for Human Cytogenetic Nomenclature, Shaffer, L.G., Tommerup N. (eds); S. Karger, Basel 2005

[Thompson-1] Thompson & Thompson Genetics in Medicine, Chapter 5, 57-74 https://www.clinicalkey.com/#!/content/book/3-s2.0-B9781437706963000054?scrollTo=%23hl0000654

[Nelson-2] Nelson Textbook of Pediatrics, Chapter 81, 604-627 https://www.clinicalkey.com/#!/content/book/3-s2.0-B9781455775668000818?scrollTo=%23hl0003126

[pmid28871159-3] Sun M, Zhang H, Li G, Guy CJ, Wang X, Lu X, Gong F, Lee J, Hassed S, Li S (September 2017). "Molecular characterization of 20 small supernumerary marker chromosome cases using array comparative genomic hybridization and fluorescence in situ hybridization". Scientific Reports. 7 (1): 10395. Bibcode:2017NatSR...710395S. doi:10.1038/s41598-017-10466-z. PMC 5583289. PMID 28871159.

[pmid26322288-4] Jafari-Ghahfarokhi H, Moradi-Chaleshtori M, Liehr T, Hashemzadeh-Chaleshtori M, Teimori H, Ghasemi-Dehkordi P (2015). "Small supernumerary marker chromosomes and their correlation with specific syndromes". Advanced Biomedical Research. 4: 140. doi:10.4103/2277-9175.161542. PMC 4544121. PMID 26322288.

[5] Baldwin, Erin L.; May, Lorraine F.; Justice, April N.; Martin, Christa L.; Ledbetter, David H. (8 February 2008). "Mechanisms and Consequences of Small Supernumerary Marker Chromosomes: From Barbara McClintock to Modern Genetic-Counseling Issues". American Journal of Human Genetics. 82 (2): 398–410. doi:10.1016/j.ajhg.2007.10.013. PMC 2427313. PMID 18252220.

[1]

[2]

[3]

[4]

[5]