Genetic disorder

For a list of genetic disorders, see List of genetic disorders.
Genetic disorder
Diagram featuring examples of a disease located on each chromosome
SpecialtyMedical genetics

A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosome abnormality. Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or chromosome.[1][2] The mutation responsible can occur spontaneously before embryonic development (a de novo mutation), or it can be inherited from two parents who are carriers of a faulty gene (autosomal recessive inheritance) or from a parent with the disorder (autosomal dominant inheritance). When the genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease. Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y chromosome or mitochondrial DNA (due to their size).[3]

There are well over 6,000 known genetic disorders,[4] and new genetic disorders are constantly being described in medical literature.[5] More than 600 genetic disorders are treatable.[6] Around 1 in 50 people are affected by a known single-gene disorder, while around 1 in 263 are affected by a chromosomal disorder.[7] Around 65% of people have some kind of health problem as a result of congenital genetic mutations.[7] Due to the significantly large number of genetic disorders, approximately 1 in 21 people are affected by a genetic disorder classified as "rare" (usually defined as affecting less than 1 in 2,000 people). Most genetic disorders are rare in themselves.[5][8]

Genetic disorders are present before birth, and some genetic disorders produce birth defects, but birth defects can also be developmental rather than hereditary. The opposite of a hereditary disease is an acquired disease. Most cancers, although they involve genetic mutations to a small proportion of cells in the body, are acquired diseases. Some cancer syndromes, however, such as BRCA mutations, are hereditary genetic disorders.[9]

  1. ^ "Genetic Disorders". Learn.Genetics. University of Utah. Archived from the original on 2022-07-15.
  2. ^ Lvovs D, Favorova OO, Favorov AV (July 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. PMC 3491892. PMID 23150804.
  3. ^ "What are the different ways in which a genetic condition can be inherited?". Genetics Home Reference. Archived from the original on 2020-09-27. Retrieved 2020-01-14.
  4. ^ "OMIM Gene Map Statistics". OMIM. Archived from the original on 2020-01-28. Retrieved 2020-01-14.
  5. ^ a b "About rare diseases". Orphanet. Archived from the original on 2019-12-17. Retrieved 2020-01-14.
  6. ^ Bick D, Bick SL, Dimmock DP, Fowler TA, Caulfield MJ, Scott RH (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. PMC 7986124. PMID 33350578.
  7. ^ a b Kumar P, Radhakrishnan J, Chowdhary MA, Giampietro PF (August 2001). "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. PMID 11499815.
  8. ^ Jackson M, Marks L, May GH, Wilson JB (December 2018). "The genetic basis of disease". Essays in Biochemistry. 62 (5): 643–723. doi:10.1042/EBC20170053. PMC 6279436. PMID 30509934. (calculated from "1 in 17" rare disorders and "80%" of rare disorders being genetic)
  9. ^ Hunt JD. "An Introduction to Cancer". Genetics and Louisiana Families. lsuhsc.edu. Archived from the original on 16 January 2020.