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.
Most genetic disorders are quite rare and 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.
- ↑ "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.
- ↑ WGBH Educational Foundation