Molecular Genetics on Endophenotype - Dictionary of Arguments
Corr I 298
Endophenotype/molecular genetics/Munafò: The concept of the endophenotype was introduced to psychiatry over thirty years ago by Gottesman and Shields (1973)(1), but its popularity is more recent: there are eight PubMed entries before the year 2000 compared to 150 in the current century. Gottesman and Shields (1973)(1) adapted the term from a 1966 paper that attributed the geographical distribution of grasshoppers to the insects’ ‘endophenotype’ (John and Lewis 1966)(2), a neologism alluding to a phenotype that was microscopic and internal, and therefore obscure to casual observation.
Def Endophenotype/Gottesman: Gottesman’s definition of an endophenotype is that it should be heritable, co-segregate with a psychiatric illness, yet be present even when the disease is not (i.e., state independent), and be found in non-affected family members at a higher rate than in the population (Gottesman and Gould 2003)(3).
The criterion of state independence was modified to take into account the importance of epigenetic and developmental factors so that the endophenotype can be manifest only at a certain age and/or after a challenge (in the same way that a glucose challenge is used for a glucose tolerance test) (Hasler, Drevets, Gould et al. 2006)(4). Others have added criteria that require endophenotypes to be part of the causal process by which disease arises (Lavori, Krause-Steinrauf, Brophy et al. 2002)(5), or at least be involved in a biologically plausible mechanism of pathogenesis (Castellanos and Tannock 2002(6); Tsuang, Faraone and Lyons 1993)(7), or, following Almasy and Blangero (2001)(8), require that an endophenotype ‘should be continuously quantifiable, should predict disorder probabilistically and should be closer to the site of primary causative agent (whether genetic or environmental) than to diagnostic categories’. It has also been suggested that ‘priority should be given to endophenotypes that are based or anchored in neuroscience’ (Doyle, Faraone, Seidman et al. 2005)(9).
1. Gottesman, I. I. and Shields, J. 1973. Genetic theorizing and schizophrenia, British Journal of Psychiatry 122: 15–30
2. John, B. and Lewis, K. R. 1966. Chromosome variability and geographic distribution in insects, Science 152: 711–21
3. Gottesman, I. I. and Gould, T. D. 2003. The endophenotype concept in psychiatry: etymology and strategic intentions, American Journal of Psychiatry 160: 636–45
4. Hasler, G., Drevets, W. C., Gould, T. D., Gottesman, I. I. and Manji, H. K. 2006. Toward constructing an endophenotype strategy for bipolar disorders, Biological Psychiatry 60: 93–105
5. Lavori, P. W., Krause-Steinrauf, H., Brophy, M., Buxbaum, J., Cockroft, J., Cox, D. R., et al. 2002. Principles, organization, and operation of a DNA bank for clinical trials: a Department of Veterans Affairs cooperative study, Controlled Clinical Trials 23: 222–39
6. Castellanos, F. X. and Tannock, R. 2002. Neuroscience of attention-deficit/hyperactivity disorder: the search for endophenotypes, Nature Neuroscience 3: 617–28
7. Tsuang, M. T., Faraone, S. V. and Lyons, M. J. 1993. Identification of the phenotype in psychiatric genetics, European Archichives of Psychiatry and Clinical Neuroscience 243: 131–42
8. Almasy, L. and Blangero, J. 2001. Endophenotypes as quantitative risk factors for psychiatric disease: rationale and study design, American Journal of Medical Genetics 105: 42–44
9. Doyle, A. E., Faraone, S. V., Seidman, L. J., Willcutt, E. G., Nigg, J. T., Waldman, I. D. et al. 2005: Are endophenotypes based on measures of executive functions useful for molecular genetic studies of ADHD?, Journal of Child Psychology and Psychiatry 46: 774-803
Marcus R. Munafò,“Behavioural genetics: from variance to DNA“, in: Corr, Ph. J. & Matthews, G. (eds.) 2009. The Cambridge handbook of Personality Psychology. New York: Cambridge University Press_____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. Translations: Dictionary of Arguments The note [Author1]Vs[Author2] or [Author]Vs[term] is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition.
Philip J. Corr
The Cambridge Handbook of Personality Psychology New York 2009
Philip J. Corr (Ed.)
Personality and Individual Differences - Revisiting the classical studies Singapore, Washington DC, Melbourne 2018