According to the Le Espanyol newspaper on January 24, the study conducted in the United Kingdom opens the door to the underlying genes for the prevention of the most serious congenital heart disease.
Down syndrome is the most common genetic disorder in humans and the leading cause of intellectual disability. Down syndrome is caused by an extra chromosome in the 21st of the 23 pairs of chromosomes in the genome: this is the root cause of many complications in this population.
Heart defects have been reported to be a less frequently mentioned complication of Down syndrome. It is estimated that about half of babies born with Down syndrome have these heart defects, such as the inability of the heart to divide into four chambers. When the observed defects are too severe, these newborns undergo high-risk surgery. Many people with Down syndrome need continuous cardiac monitoring throughout their lives.
In this regard, the Francis Crick Institute and University College London have taken another step forward in their understanding of Down syndrome. A joint study published Wednesday in the journal Science Translational Medicine found specific genes that appear to be responsible for these heart defects. This also opens the door to potential targeting of these defects in the future, as they have succeeded in partially reversing these defects by reducing the overactivity of this gene.
To achieve this milestone, the researchers studied the hearts of human fetuses with Down syndrome as well as the embryonic hearts of mice with this syndrome. The extra chromosome in chromosome 21, the 21st pair of chromosomes that characterize Down syndrome, has 230 genes, and through genetic mapping, scientists have succeeded in detecting the gene that causes the heart defect. The study pointed to the gene as DYRK1A, which has previously been linked to facial changes and cognitive decline.
Jenny Lawrence, a professor of neurology and pediatrics at the University of Massachusetts, told the Center for Science Media: "This study comes from a team of reputable scientists who have long studied congenital heart disease in mouse models of Down syndrome. Their study identified the congenital heart disease driver gene dyrk1a, which has been linked to the effects of Down syndrome in other studies. Therefore, it is almost certainly a very important gene. ”
In any case, until then, its relationship with heart development in Down syndrome was unclear. Specifically, people with Down syndrome have an extra copy of DYRK1A, which inhibits genes that are essential for the cellular** and mitochondrial function of the developing heart. These changes may cause the atria and ventricles to be unable to separate properly in mice. It doesn't seem to be the only gene associated with this, though. Scientists are already looking for a possible second related gene.
In the second part of the study, the experts verified that inhibition of the enzyme encoding the gene could improve the heart health of mice carrying three copies of the dyrk1a gene. Victor Tibrevicz, head of the Immune Cell Biology Laboratory and Down Syndrome Laboratory at the Francis Crick Institute, said this could lead to a potential approach. (Compiled by Su Jiawei).
Schematic diagram of the gene (Xinhua News Agency).