
A new study has found that the extra copy of Chromosome 21 that causes Down's syndrome throws a spanner into the workings of all the other chromosomes as well.
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.
Advertisement
The twins were born from a single egg that split, which means their DNA code started off identical.
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.
People with Down's Syndrome, about one in every 750, have a third, extra Chromosome 21 -- the smallest of all the chromosomes with about one percent 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.
Source: AFP
Advertisement
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.
People with Down's Syndrome, about one in every 750, have a third, extra Chromosome 21 -- the smallest of all the chromosomes with about one percent 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.
Source: AFP
Advertisement
Advertisement
|
Advertisement
Recommended Readings
Latest Genetics & Stem Cells News

Among MS patients, the stem cells showed a neuroprotective role, guarding nerve cells from further decline.

New possibilities for research on digestive diseases have been set by complete decoding of the Y chromosome.

UK has given the green light to the world's inaugural gene therapy for sickle-cell disease and thalassemia.

1 in 25 people had a genotype linked to short lifetime, which includes BRCA2 and LDLR genes, that reduced lifespan by seven years, and six years respectively.

The study findings help redefine osteoarthritis as a reversible loss of key cartilage stem cells, not just 'wear and tear'."