Editing Collagen (section)

==Diseases==
One thousand mutations have been identified in 12 out of more than 20 types of collagen. These mutations can lead to various diseases at the tissue level.<ref name="Mahajan, VB 2010">{{cite journal | vauthors = Mahajan VB, Olney AH, Garrett P, Chary A, Dragan E, Lerner G, Murray J, Bassuk AG | title = Collagen XVIII mutation in Knobloch syndrome with acute lymphoblastic leukemia | journal = American Journal of Medical Genetics. Part A | volume = 152A | issue = 11 | pages = 2875–2879 | date = November 2010 | pmid = 20799329 | pmc = 2965270 | doi = 10.1002/ajmg.a.33621 }}</ref>

[[Osteogenesis imperfecta]] – Caused by a mutation in ''type 1 collagen'', dominant autosomal disorder, results in weak bones and irregular connective tissue, some cases can be mild while others can be lethal. Mild cases have lowered levels of collagen type 1 while severe cases have structural defects in collagen.<ref>{{cite journal | vauthors = Gajko-Galicka A | title = Mutations in type I collagen genes resulting in osteogenesis imperfecta in humans | journal = Acta Biochimica Polonica | volume = 49 | issue = 2 | pages = 433–441 | year = 2002 | pmid = 12362985 | doi = 10.18388/abp.2002_3802 | url = http://www.actabp.pl/pdf/2_2002/433-441.pdf | url-status = live | doi-access = free | archive-url = https://web.archive.org/web/20130607085009/http://www.actabp.pl/pdf/2_2002/433-441.pdf | archive-date = 7 June 2013 }}</ref>

[[Chondrodysplasia]]s – Skeletal disorder believed to be caused by a mutation in ''type 2 collagen'', further research is being conducted to confirm this.<ref name="pmid2624272">{{cite journal | vauthors = Horton WA, Campbell D, Machado MA, Chou J | title = Type II collagen screening in the human chondrodysplasias | journal = American Journal of Medical Genetics | volume = 34 | issue = 4 | pages = 579–583 | date = December 1989 | pmid = 2624272 | doi = 10.1002/ajmg.1320340425 }}</ref>

[[Ehlers–Danlos syndrome]] – Thirteen different types of this disorder, which lead to deformities in connective tissue, are known.<ref>{{cite journal | vauthors = Malfait F, Francomano C, Byers P, Belmont J, Berglund B, Black J, Bloom L, Bowen JM, Brady AF, Burrows NP, Castori M, Cohen H, Colombi M, Demirdas S, De Backer J, De Paepe A, Fournel-Gigleux S, Frank M, Ghali N, Giunta C, Grahame R, Hakim A, Jeunemaitre X, Johnson D, Juul-Kristensen B, Kapferer-Seebacher I, Kazkaz H, Kosho T, Lavallee ME, Levy H, Mendoza-Londono R, Pepin M, Pope FM, Reinstein E, Robert L, Rohrbach M, Sanders L, Sobey GJ, Van Damme T, Vandersteen A, van Mourik C, Voermans N, Wheeldon N, Zschocke J, Tinkle B | title = The 2017 international classification of the Ehlers-Danlos syndromes | journal = American Journal of Medical Genetics. Part C, Seminars in Medical Genetics | volume = 175 | issue = 1 | pages = 8–26 | date = March 2017 | pmid = 28306229 | doi = 10.1002/ajmg.c.31552 | s2cid = 4440499 | doi-access = free }}</ref> Some of the rarer types can be lethal, leading to the rupture of arteries. Each syndrome is caused by a different mutation. For example, the vascular type (vEDS) of this disorder is caused by a mutation in ''collagen type 3''.<ref name=Hamel>{{cite journal | vauthors = Hamel BC, Pals G, Engels CH, van den Akker E, Boers GH, van Dongen PW, Steijlen PM | title = Ehlers-Danlos syndrome and type III collagen abnormalities: a variable clinical spectrum | journal = Clinical Genetics | volume = 53 | issue = 6 | pages = 440–446 | date = June 1998 | pmid = 9712532 | doi = 10.1111/j.1399-0004.1998.tb02592.x | s2cid = 39089732 }}</ref>

[[Alport syndrome]] – Can be passed on genetically, usually as X-linked dominant, but also as both an autosomal dominant and autosomal recessive disorder, those with the condition have problems with their kidneys and eyes, loss of hearing can also develop during the childhood or adolescent years.<ref>{{cite book | vauthors = Kashtan CE |year=1993 |volume=Collagen IV-Related Nephropathies |chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK1207/ |chapter=Alport Syndrome and Thin Basement Membrane Nephropathy | veditors = Pagon RA, Bird TD, Dolan CR, Stephens K, Adam MP |title=GeneReviews |publisher=University of Washington, Seattle |location=Seattle WA |pmid=20301386}}</ref>

[[Knobloch syndrome]] – Caused by a mutation in the [[COL18A1]] gene that codes for the production of collagen XVIII. Patients present with protrusion of the brain tissue and degeneration of the retina; an individual who has family members with the disorder is at an increased risk of developing it themselves since there is a hereditary link.<ref name="Mahajan, VB 2010"/>