Why do people with down syndrome look alike?

It’s an interesting aspect of this disease; sharing facial features with anyone else that inhabits Down Syndrome. It’s unfortunate, but because of this characteristic it is quite easy to pinpoint someone who is dealing with this disability. This is quite unique from most other disabilities, however. Things like autism and ADHD don’t give any kind of inkling as to whether this individual carries it, which begs the question, what is it about Down Syndrome that gives away this appearance.

Let’s first crack down on what down syndrome actually is. According to the National Down Syndrome Society, the typical nucleus of a human cell is supposed to carry 23 pairs of chromosomes, but down syndrome occurs when an individual has a full or partial copy of chromosome 21. One in every 691 babies are born with Down Syndrome in the U.S. It is known as the most common genetic condition. This disability was first identified in the late nineteenth century when John Langdon Down, an English physician, published work acknowledging an accurate description of Down Syndrome and realizing the disease was a major and separate entity that deserved it’s own recognition. It wasn’t until 1959, that great advances in the research of this disease were made. French physician, Jerome Lejeune, was the first to identify the disease as a chromosomal condition. “Instead of the usual 46 chromosomes present in each cell, Lejeune observed 47 in the cells of individuals with Down Syndrome.” It was later determined that an extra copy or partial copy of the chromosome 21 was a direct correlation to characteristics associated with Down Syndrome.

The source, Quora, goes into fine detail about the typical Down Syndrome appearance. An abnormally small chin, up slanting palpebral eye fissures on the inner corner of the eyes, and corners of the mouth are turned down. Down Syndrome patients have muscle hypotonia, where their limbs aren’t stiff and well controlled like the average person, they’re “floppy” and mostly just hang there. They have a flat nasal bridge and a protruding tongue. Their face is flat and broad, and they have a short neck. There’s a large gap between the big toe and the other toes. They have short fingers and they’re also short in height. A person suffering from Down Syndrome, however, does not have to have every single one of these features.

“The chromosomes are holders of the genes, those bits of DNA that direct the production of a wide array of materials the body needs,” says Mark A. Griffin, a father with a child dealing with Down Syndrome. In chromosome 21, the presence of an extra set of genes can lead to “over expression.” In most genes, over expression has little effect on the body, but Down Syndrome genes seem to reject that alternative hypothesis. The question of which genes are directly correlated with the similar appearances of Down Syndrome patients is still a mystery. Scientists have come to a false positive conclusion that yes, these genes have to be causing the deformities in these individual’s appearances, but what exact genes they are is still too difficult to identify.

Down Syndrome children are still possibly the cutest things ever

Down Syndrome children are still possibly the cutest things ever

 

One thought on “Why do people with down syndrome look alike?

  1. Emily Lippincott

    I have also wondered this for a long time, and I have also noticed that there is a similar appearance in dwarfism as well. Not only do they look similar, but people with dwarfism also look older than the age they actually are, especially children with dwarfism. Take a look at this article I found discussing more about dwarfism and this common appearance, I think you will find it interesting after you writing this blog post.

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