advertisement
22 April 2014

Down's chromosome affects all other chromosomes

The additional chromosome that causes Down's syndrome has a knock-on effect on all the 22 other chromosomes, according to a study.

0

The extra copy of Chromosome 21 that causes Down's syndrome throws a spanner into the workings of all the other chromosomes as well, said a study that surprised its authors.

Using data from a set of twins, one with Down's and one without, researchers found a major difference in how genes functioned between the two.

The twins were born from a single egg that split, which means their DNA code started off identical.

Read: 10 Down syndrome facts

Knock-on effect

But the individual with Down's had an extra copy of Chromosome 21 – a difference enabling the scientists to see how this might affect the same genome.

The additional chromosome had a knock-on effect on all the 22 other chromosomes, the team reported in the journal Nature.

"We were very surprised by this finding," said Audrey Letourneau of the University of Geneva Medical School who co-authored the study.

"It seems that this small, extra chromosome has a major influence on the entirety of the genome."

Chromosomes are made up of bundles of DNA called genes, which hold the information for cell function.

Humans have 23 pairs of chromosomes – or a total of 46 per cell.

Genetically caused mental disease

People with Down's Syndrome, about one in every 750, have a third, extra Chromosome 21 – the smallest of all the chromosomes with about1% of the DNA in a cell.

Down's is the world's leading genetically-caused mental disease, and also carries a heightened risk of heart defects, leukaemia, immune-system malfunction and premature Alzheimer's disease.

The results may help researchers "find substances that could reverse this gene-expression dysregulation, i.e. drugs that revert the expression of genes... back to normal," co-author Stylianos Antonarakis told AFP.

Read more:
Could Down Syndrome be reversed?
New Down syndrome theory

Early testing effective for Down Syndrome

 
NEXT ON HEALTH24X
advertisement

Read Health24’s Comments Policy

Comment on this story
0 comments
Comments have been closed for this article.

Live healthier

Contraceptives and you »

Scientists create new contraceptive from seaweed Poor long-term birth control training leads to 'accidents'

7 birth control myths you should stop believing

Will the Pill make you gain weight? Can you fall pregnant while breastfeeding? We bust seven common myths about birth control.

Your digestive health »

Causes of digestive disorders 9 habits that could hurt your digestive system

Your tummy rumblings might help diagnose bowel disorder

With the assistance of an 'acoustic belt', doctors can now determine the cause of your tummy troubles.