U.S. DOE, HUMAN GENOME PROJECTThe deleterious effects of trisomy 21—the extra chromosome behind Down’s syndrome—can be seen across the entire genome, according to a study published today (April 16) in Nature. While studying a pair of monozygotic twins in which only one person had Down’s syndrome, a team led by Stylianos Antonarakis of the University of Geneva Medical School in Switzerland discovered that trisomy 21 can affect other chromosomes.
This rare twin pair allowed the researchers to compare the effects of Down’s syndrome on gene expression in two otherwise genetically identical individuals. The researchers found that in the twin with Down’s syndrome, genes in territories along the chromosomes that are highly expressed in people without the disorder showed reduced expression, while genes in territories that are normally suppressed were more highly expressed.
“The fact that they’ve got these really nice domain structures genome-wide further implicates the rising perception of...