Sexual desire linked to genes
Differences in sexual desire can be attributed to genetic variances. Researchers
say that sexual "problems" will thus be rerouted from the classical
psychological couch into the realm of 21st century, genomics-based medicine.
New evidence that individual differences in human sexual desire can be
attributed to genetic variations has been revealed by a research group headed by
a professor of psychology at the Hebrew University of Jerusalem. The findings
are believed to have an impact on people's understanding of their own sexuality
as well as to how sexual disorders may come to be treated in the future.
The study represents the combined efforts of researchers directed by Prof.
Richard P. Ebstein, of Herzog Hospital and the head of the Scheinfeld Center for
Human Genetics in the Social Sciences of the Psychology Department at the Hebrew
University, and a research group headed by Prof. Robert H. Belmaker of the
Psychiatry Division of Ben Gurion University of the Negev.
The article provides, for the first time, data that common variations in the
sequence of DNA impact on sexual desire, arousal and function and lead to
differences and diversity of the human sexual phenotype.
The implications of these findings are far-reaching, say the researchers, and
represent a revolutionary change in the way society, and especially psychology,
may come to regard this central element of human behavior.
Little has been known regarding the biological basis for individual
differences in normal, human sexual behavior. Most significant variations in the
expression of human sexuality are considered historically to be the result of
learned behavior or psychological problems. However, recent advances in
molecular genetic studies of human behavior and personality, imaging studies of
sexual arousal and performance, and neuroendocrinological investigations suggest
that individual variations in many aspects of human sexuality, similar to other
human behavior, are likely to rest on a firm foundation in the neurosciences.
This progress in understanding the biological basis of human sexuality
provides a new way of viewing variations in sexual norms, without passing moral
judgment.
In this latest study, the Israeli investigators examined the DNA of 148
healthy male and female Israeli university students and compared the results
with questionnaires asking for the students' self-descriptions of their sexual
desire, arousal and sexual function. The results showed a correlation between
variants in the D4 receptor gene - which is responsible for producing the
dopamine receptor protein (DRD4) - and the students' self-reports on sexuality.
Interestingly, some forms of variants in this gene were shown to have a
depressing effect on sexual desire, arousal and function, while other common
variant had the opposite effect - an increase in the sexual desire score. The
latter is believed to be a relatively new mutation, and it is estimated that it
appears in Homo sapiens "only" 50,000 years ago at the time of
humankind's great exodus from Africa. Approximately 30% of many populations
carry the heightened arousal mutations, while around 60% carry the depressant
mutation.
The investigators predict that as a result of their work, and other advances
in neurosciences focusing on sexual behavior, a conceptual change will result,
in which new therapeutic pathways will be developed for treatment of sexual
dysfunctions based on a rational pharmacogenetic strategy. Additionally, the
investigators note that many variations such as "low sexual desire"
may be quite normal and not necessarily a product of dysfunction.
It is possible, therefore, say the researchers, that sexual
"problems" will thus be rerouted to a great extent from the classical
psychological couch into the realm of 21st century, genomics-based medicine.
More information:
 Contact:
Jerry Barach
jerryb@savion.huji.ac.il
The Hebrew University of Jerusalem
An article on the topic appears currently in Molecular Psychiatry
online.
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