It was once a death sentence and feared as a transmittable disease. Children with the condition were often perceived as “retarded” and incapable of coexisting with others in society. However, as modern medicine and research propelled us into the 21st century, these misconceptions regarding those with Down syndrome were one by one confined to the pages of the past.
Research today estimates that around 6,000 children are born with Down syndrome every year in the United States alone. Also known as trisomy 21, the syndrome is a genetic condition that occurs when an individual has additional copies of chromosome 21 in some or all of their cells. A human being’s body is comprised of cells that each typically contain 46 chromosomes divided into 23 numbered pairs. Each parent contributes one chromosome to each pair, resulting in 23 chromosomes coming from the mother and 23 from the father. If an abnormality occurs during development in utero, some or all of an embryo’s cells could contain three copies of chromosome 21.
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Although Down syndrome is a genetic disorder, 95% of cases are not inherited. To this day, scientists have still not concluded what triggers and results in the chromosome 21 abnormality. Studies to date have noted a positive correlation between the heightened risk of Down syndrome and the increasing age of mothers 35 and older, but no other environmental causes. The risk of having another child with Down syndrome also increases once a mother has already had one child with the condition. However, with more advanced medical technology today, mothers can conduct prenatal screens and diagnostic tests to determine before birth if their child would be born with Down syndrome, allowing for the families to be informed and make preparations accordingly.
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Children born with Down syndrome often have flatter faces, upward-slanting eyes, and short statures. Aside from these physical similarities, those with Down syndrome also often exhibit certain intellectual or cognitive disabilities, ranging in severity. It is not uncommon for those with the disorder to have distinct but deleterious health issues, including heart conditions, obesity, dementia, and even leukemia. For more than half a century it was unknown why individuals with Down syndrome were more likely to be diagnosed with leukemia. However, researchers in a recent study conducted in 2014 at the Dana-Farber Cancer Institute were finally able to find the long sought after answer. Using mice models, they discovered that those with Down syndrome contain an additional copy of the gene HMGN1, which has the ability to silence a subset of proteins referred to as PRC2. These proteins in turn control a set of genes that when unregulated result in cells in the body becoming cancerous.
Back in 1910, the idea that a child with Down syndrome could live well past the age of ten was simply preposterous. Now, in 2018, around 80% of individuals with Down syndrome are able to not only survive to the age of 60 but also attend school and pursue careers. Just over 100 years later, increases in medical technology and research have both dramatically extended the lifespan of those with Down syndrome as well as paved the way to dispelling deep-rooted stigmas surrounding the condition. Today, we have been able to find the answers to a number of the whys and hows surrounding Down syndrome, but in many ways, we are only just scratching the surface.
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