Encyclopedia of Behavioral Medicine

2013 Edition
| Editors: Marc D. Gellman, J. Rick Turner


  • Rong Jiang
Reference work entry
DOI: https://doi.org/10.1007/978-1-4419-1005-9_712


Penetrance in genetics is the proportion of individuals carrying a particular gene variant (allele or genotype) that also possess an associated trait (phenotype). If penetrance of a disease allele is 100%, then all individuals carrying that allele will have the associated disease. Penetrance only considers whether individuals express the trait or not. This differs from expressivity, which characterizes qualitatively or quantitatively the extent of phenotypic variation given a particular genotype. Penetrance is age related (Bessett et al., 1998) and is affected by environmental and behavioral factors such as diet and smoking. It is also modified by other genes and epigenetic regulation.


References and Readings

  1. Bessett, J. H., Forbes, S. A., Pannett, A. A. J., Lloyd, S. E., Christie, P. T., Wooding, C., et al. (1998). Characterization of mutations in patients with multiple endocrine neoplasia type 1. American Journal of Human Genetics, 62(2), 232–244.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, New York 2013

Authors and Affiliations

  1. 1.Department of Psychiatry and Behavioral SciencesDuke UniversityDurhamUSA