Identical twins not as identical as believed

Feb 15, 2008

Contrary to our previous beliefs, identical twins are not genetically identical. This surprising finding is presented by American, Swedish, and Dutch scientists in a study being published today in the prestigious journal American Journal of Human Genetics. The finding may be of great significance for research on hereditary diseases and for the development of new diagnostic methods.

How can it be that one identical twin might develop Parkinson’s disease, for instance, but not the other? Until now, the reasons have been sought in environmental factors. The current study complicates the picture.

“Even though the genome is virtually identical in identical twins, our results show that there in fact are tiny differences and that they are relatively common. This could have a major impact on our understanding of genetically determined disorders,” says Jan Dumanksi, who co-directed the international study with his colleague Carl Bruder.

“By uncovering these small genetic differences in identical twins where one of them is sick, we have a way of tying specific genetic changes to the genesis of common diseases,” says Carl Bruder.

These researchers studied 19 pairs of identical twins and found that they indeed had the same DNA but nevertheless evinced differences in the number of copies of individual DNA segments. A segment might be missing, or more copies might exist in one twin. This could explain how one identical twin can be afflicted with a disorder while the other twin remains fully healthy, according to the scientists.

Source: Uppsala University

Explore further: Tests will track improved thinking in people with fragile X, down syndromes

add to favorites email to friend print save as pdf

Related Stories

First Copernicus satellite now operational

Oct 06, 2014

With the commissioning of Sentinel-1A completed and the satellite's transfer to the team in charge of its exploitation, its data are available as of today to all users.

NASA HS3 instrument views two dimensions of clouds

Sep 16, 2014

NASA's Cloud Physics Lidar (CPL) instrument, flying aboard an unmanned Global Hawk aircraft in this summer's Hurricane and Severe Storm Sentinel, or HS3, mission, is studying the changing profile of the atmosphere ...

Sentinel-1 poised to monitor motion

Aug 27, 2014

Although it was only launched a few months ago and is still being commissioned, the new Sentinel-1A radar satellite has already shown that it can be used to generate 3D models of Earth's surface and will ...

Identical twins offer up selves for space science

May 28, 2014

Astronauts Scott and Mark Kelly will take part in an unprecedented study of identical twins to better understand the effects of prolonged weightlessness by comparing the twin in space with the twin on the ...

Identical twins begin polar trek

Apr 29, 2014

Identical twins - Hugo and Ross Turner – will begin a unique expedition across the polar ice cap of Greenland this week, during which researchers at King's will study how modern clothes, food and equipment ...

NASA to conduct unprecedented twin experiment

Apr 11, 2014

Consider a pair of brothers, identical twins. One gets a job as an astronaut and rockets into space. The other gets a job as an astronaut, too, but on this occasion he decides to stay home. After a year ...

Recommended for you

Changes in scores of genes contribute to autism risk

Oct 29, 2014

Small differences in as many as a thousand genes contribute to risk for autism, according to a study led by Mount Sinai researchers and the Autism Sequencing Consortium (ASC), and published today in the journal Nature.

Dozens of genes associated with autism in new research

Oct 29, 2014

Two major genetic studies of autism, led in part by UC San Francisco scientists and involving more than 50 laboratories worldwide, have newly implicated dozens of genes in the disorder. The research shows ...

Genetic link to kidney stones identified

Oct 29, 2014

A new breakthrough could help kidney stone sufferers get an exact diagnosis and specific treatment after genetic links to the condition were identified.

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

googleplex
3 / 5 (3) Feb 15, 2008
Ok the infamous Physorg bogus headline strikes again.
It should say "indentical twins used to find disease genotypes".
It is implicit in what the article says that 'theoretically ideal' identical twins have genetically identical DNA. However in practice mutations can occur to one twin that cause small differences. In some instances this can be used to identify disease genotypes.
gopher65
1 / 5 (1) Feb 16, 2008
Indeed googleplex. My thoughts exactly.
superhuman
not rated yet Feb 25, 2008
No, the title is correct. The article says that there are more differences between homozygous twins then there should be according to our current knowledge.
And "indentical twins used to find disease genotypes" is no news its been like that for decades.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.