A genetic disorder is a health problem caused by abnormalities in the genome. They are heritable, and may be passed down from the parents' genes to their children and to later generations. If a genetic disorder is present from birth, it is described as a congenital defect. Some defects only show up in later life.
The mutation responsible can occur spontaneously before the embryo develops, or it can be inherited from parents who are carriers of a faulty gene.
There are well over 6,000 known genetic disorders, and new genetic disorders are constantly being found. More than 600 genetic disorders are treatable. Around 1 in 50 people are affected by a known single-gene disorder, while around 1 in 263 are affected by a disorder caused by their chromosomes. Parts of a chromosome may be absent, or duplicated.
About 65% of people have some kind of health problem as a result of congenital genetic mutations. About 1 in 21 people are affected by a genetic disorder classified as "rare" (less than 1 in 2,000 people). Most genetic disorders are rare in themselves. They may affect one person in every several thousands or even millions. Sometimes they are relatively frequent in a population. If they are frequent, it suggests these recessive gene disorders give an advantage in certain environments when only one copy of the gene is present. Sickle cell anaemia is an example of this.
The same disease, such as some forms of cancer, may be caused by an inherited genetic condition in some people, by new mutations in other people, and by nongenetic causes in still other people. A disease is only called a genetic disease if it can be inherited at birth. The particular defect may only show up later in life.
- ↑ "Genetic Disorders". learn.genetics.utah.edu. Retrieved 2019-07-01.
- ↑ Lvovs, D.; Favorova, O.O.; Favorov, A.V. (2012). "A Polygenic Approach to the Study of Polygenic Diseases". Acta Naturae. 4 (3): 59–71. doi:10.32607/20758251-2012-4-3-59-71. ISSN 2075-8251. PMC 3491892. PMID 23150804.
- ↑ "OMIM Gene Map Statistics". www.omim.org. Retrieved 2020-01-14.
- ↑ 4.0 4.1 "Orphanet: About rare diseases". www.orpha.net. Retrieved 2020-01-14.
- ↑ Bick, David; Bick, Sarah L.; Dimmock, David P.; Fowler, Tom A.; Caulfield, Mark J.; Scott, Richard H. (March 2021). "An online compendium of treatable genetic disorders". American Journal of Medical Genetics. Part C, Seminars in Medical Genetics. 187 (1): 48–54. doi:10.1002/ajmg.c.31874. ISSN 1552-4876. PMC 7986124. PMID 33350578.
- ↑ 6.0 6.1 Kumar, Pankaj; Radhakrishnan, Jolly; Chowdhary, Maksud A.; Giampietro, Philip F. (2001-08-01). "Prevalence and Patterns of Presentation of Genetic Disorders in a Pediatric Emergency Department". Mayo Clinic Proceedings. 76 (8): 777–783. doi:10.4065/76.8.777. ISSN 0025-6196. PMID 11499815.
- ↑ Jackson, Maria; Marks, Leah; May, Gerhard H.W.; Wilson, Joanna B. (2018-12-03). "The genetic basis of disease". Essays in Biochemistry. 62 (5): 643–723. doi:10.1042/EBC20170053. ISSN 0071-1365. PMC 6279436. PMID 30509934.
(calculated from "1 in 17" rare disorders and "80%" of rare disorders being genetic)
- ↑ WGBH Educational Foundation