A study of over 380,000 people, published today in
the journal Nature Genetics, has identified gene
differences that influence the age of puberty,
sexual intercourse and first birth.
This study shows that genetic factors that act on
biological mechanisms, such as the timing of
childhood physical maturity and personality, also
contribute to the timing of sexual behaviour, and in
this cohort genetic factors accounted for around 25%
of the variation in the age at which individuals
first had sexual intercourse.
Age at first sexual intercourse is known to be
influenced by social and family factors, such as
peer pressure, but this study shows that genetic
factors also have an influence on the timing of this
sexual behaviour.
It is known from other studies that first sexual
intercourse at an early age is associated with
adverse educational achievements, physical health
and mental wellbeing.
To identify the gene differences which influence
timing of sexual behaviour, the researchers at the
MRC Epidemiology Unitopens in new window University
of Cambridge analysed the genetic data of 59,357 men
and 66,310 women aged between 40 and 69 years old
part of UK Biobank, a national study for health
research.
This analysis identified 38 gene variants that were
associated with age at first sexual intercourse. The
researchers confirmed this association in two
independent datasets, 241,910 men and women in the
deCODE Study in Iceland and 20,187 participants in
the Women’s Genome Health Study in the USA, to total
a sample of over 380,000.
Several of these gene variants were located in or
near genes previously implicated in brain
development and neural connections, and their
analysis uncovered associations with a range of
reproductive behaviours, such as age at first birth
and number of children.
Dr John Perry, a senior investigator scientist at
the MRC Epidemiology Unit, and a lead author of the
paper, said: “While social and cultural factors are
clearly relevant, we show that age at first sexual
intercourse is also influenced by genes which act on
the timing of childhood physical maturity and by
genes which contribute to our natural differences in
personality types.
“One example is a genetic variant in CADM2, a gene
that controls brain cell connections and brain
activity, which we found was associated with a
greater likelihood of having a risk-taking
personality, and with an earlier age at first sexual
intercourse and higher lifetime number of children.”
In previous studies by the same team, it was found
that an earlier age at puberty is linked to
increased long-term risks for diseases such as
diabetes, heart disease and some cancers.
Dr Ken Ong, a paediatrician and programme leader at
the MRC Epidemiology Unit, and a lead author on the
paper, added: “We have already shown that early
puberty and rapid childhood growth adversely affect
disease risks in later life, but we have now shown
that the same factors can have a negative effect at
a much younger age, including earlier sexual
intercourse and poorer education attainment.”
The investigators hope that future preventive
efforts to delay puberty in young children, for
example by avoiding excess childhood weight gain,
will have benefits both on reducing adolescent
risk-taking behaviours and for their future health
as adults.
See also
Timing of puberty has wide-ranging impacts on health
in later life (2015-06-19)
Link...
For more information
Felix R. Day, Hannes Helgason, Daniel I. Chasman,
Lynda M. Rose, Po-Ru Loh, Robert A. Scott, Agnar
Helgason, Augustine Kong, Gisli Masson, Olafur Th.
Magnusson, Daniel Gudbjartsson, Unnur
Thorsteinsdottir, Julie E. Buring, Paul M. Ridker,
Patrick Sulem, Kari Stefansson, Ken K. Ong, John
R.B. Perry “Physical and neuro-behavioural determinants of reproductive onset and success”.
Nature Genetics. Published online 18 April 2016.
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Medical Research Council
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