Double identities lie behind chromosome disorders

July 8, 2007

Chromosome disorders in sex cells cause infertility, miscarriage and irregular numbers of chromosomes (aneuploidy) in neonates. A new study from Karolinska Institutet published in the scientific journal Nature Genetics shows how chromosome disorders can arise when sex cells are formed.

Sex cells contain a control station for monitoring the mechanism that ensures that the correct numbers of chromosomes are distributed during cell division. Scientists have now shown that there is an alternative distribution mechanism in female sex cells that cause chromosome disorders. Aberrant chromosomes orientate themselves like normal chromosomes, and this ability to adopt double identities protects them from detection by the control centre.

“We believe that this new fundamental mechanism can help to explain why chromosome disorders are so common in female sex cells,” says Professor Christer Höög, leader of the study.

The research might eventually lead to new medical treatments able to reduce the risk of foetal damage.

Over 0.3 per cent of children are born with some kind of chromosome disorder. Most develop Downs Syndrome, or obtain the wrong number of sex chromosomes and develop Turner’s or Klinefelter’s syndrome. Turner’s syndrome only occurs in females and is caused when one of the two X chromosomes is missing. Girls with Turner’s have arrested development and if no treatment is given do not enter puberty. Klinefelter’s syndrome affects males, who receive an extra X chromosome. Symptoms include concentration difficulties, poor motor skills and infertility.

Publication: “Bi-orientation of achiasmatic chromosomes in mammalian MI oocytes contributes to aneuploidy”, Anna Kouznetsova, Lisa Lister, Magnus Nordenskjöld, Mary Herbert, Christer Höög, Nature Genetics, 8 July 2007

Source: Karolinska Institutet

Explore further: Intersex—seeking the beauty in difference

Related Stories

Intersex—seeking the beauty in difference

October 4, 2016

At 13 years old, Sean Saifa Wall was admitted to hospital with pain in his groin. He says that he was given very little information about what might be causing it, and doctors didn't discuss different options for treatment ...

Opinion: Why I hate the term '3-parent baby'

September 30, 2016

A healthy baby boy has been born following mitochondrial manipulation technology (MMT). It was bound to happen, and might offer an alternative for some women who carry a mitochondrial disease.

Sex hormones skew outcomes in clinical trials—here's how

August 9, 2016

Clinical research often excludes females from their trials under the assumption that "one size fits all," that a painkiller or antidepressant will be equally effective in subjects of either sex, but a growing number of scientists ...

Recommended for you

Scientists edit gene mutations in inherited form of anemia

October 26, 2016

A Yale-led research team used a new gene editing strategy to correct mutations that cause thalassemia, a form of anemia. Their gene editing technique provided corrections to the mutations and alleviated the disease in mice, ...


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.