Additive genetics

Additive genetics are genes that add together to create an effect on a trait. It happens if multiple genes affect the same trait or phenotype. This can be genes for height or genes for if someone gets a disease.[1][2] For example, one gene might cause someone to be a millimeter taller. A different gene might cause someone to be two millimeters taller. Since the effect of the genes add together, having both of these genes would result in being three (one plus two) millimeters taller.

When genes do not add together, it is called dominance or epistasis, which can be important for Menedelian (single-gene) diseases. Sometimes, even when there are some dominant genes, additive genetics can be more important.[3]

Complex traits are usually determined by many genes which add together.[4][5] For example, dominance is not important compared to additive genetics for some traits,[3][6][7] including height, weight, blood pressure, and heart rate.[3]

References

  1. ↑ Rieger, R.; Michaelis, A.; Green, M.M. (1968), A glossary of genetics and cytogenetics: Classical and molecular, New York: Springer-Verlag, ISBN 9780387076683
  2. ↑ "Medical Definition of Additive genetic effects". Archived from the original on 2013-03-11. Retrieved 2023-07-17.
  3. ↑ 3.0 3.1 3.2 Zhu, Zhihong; Bakshi, Andrew; Vinkhuyzen, Anna A.E.; Hemani, Gibran; Lee, Sang Hong; Nolte, Ilja M.; van Vliet-Ostaptchouk, Jana V.; Snieder, Harold; Esko, Tonu; Milani, Lili; Mägi, Reedik; Metspalu, Andres; Hill, William G.; Weir, Bruce S.; Goddard, Michael E. (2015). "Dominance Genetic Variation Contributes Little to the Missing Heritability for Human Complex Traits". The American Journal of Human Genetics. 96 (3): 377–385. doi:10.1016/j.ajhg.2015.01.001. ISSN 0002-9297. PMC 4375616. PMID 25683123.
  4. ↑ Crow, James F. (2010-04-27). "On epistasis: why it is unimportant in polygenic directional selection". Philosophical Transactions of the Royal Society B: Biological Sciences. 365 (1544): 1241–1244. doi:10.1098/rstb.2009.0275. ISSN 0962-8436. PMC 2871814. PMID 20308099.
  5. ↑ Mäki-Tanila, Asko; Hill, William G (2014-07-01). "Influence of Gene Interaction on Complex Trait Variation with Multilocus Models". Genetics. 198 (1): 355–367. doi:10.1534/genetics.114.165282. ISSN 1943-2631. PMC 4174947. PMID 24990992.
  6. ↑ Hivert, Valentin; Sidorenko, Julia; Rohart, Florian; Goddard, Michael E.; Yang, Jian; Wray, Naomi R.; Yengo, Loic; Visscher, Peter M. (2021). "Estimation of non-additive genetic variance in human complex traits from a large sample of unrelated individuals". The American Journal of Human Genetics. 108 (5): 786–798. doi:10.1016/j.ajhg.2021.02.014. PMC 8205999. PMID 33811805.
  7. ↑ Pazokitoroudi, Ali; Chiu, Alec M.; Burch, Kathryn S.; Pasaniuc, Bogdan; Sankararaman, Sriram (2021). "Quantifying the contribution of dominance deviation effects to complex trait variation in biobank-scale data". The American Journal of Human Genetics. 108 (5): 799–808. doi:10.1016/j.ajhg.2021.03.018. ISSN 0002-9297. PMC 8206203. PMID 33811807.