this question Genetic Engineer Dilara SarıWe have referred it to. Yourself Instagram, twitter and YouTubeHe enlightens hundreds of thousands of people by telling about genetic research, biological systems and scientific developments.

This time As a guest of Webtekno will inform many of our readers about an important genetic science. Here are our questions and Dilara’s answers:

Why do people with Down syndrome have 47 chromosomes instead of 46?

In individuals without any chromosomal abnormality, total 46 chromosomes 1 pair of these chromosomes are sex chromosomes. That is, there are 22 pairs of autosomal chromosomes. The condition in which these chromosome pairs are triplicate instead of double is called trisomy. Down syndrome is usually a trisomy on the 21st chromosome, so it is not 46 in individuals with Down syndrome. 47 chromosomes consists.

There are different types of Down syndrome. What exactly are the differences between them?

Mosaic Down Syndrome In the case of the first fertilization, while there are actually 46 chromosomes, some cells have 47 chromosomes because of an anomaly that develops later. Some of the person’s cells carry 46 chromosomes and some cells carry 47 chromosomes. The regions where 47 chromosomes are most prominent are the regions most affected by the syndrome. For example, if 46 chromosomes are observed in the cells of the nervous system, and not 47, the person’s IQ level will not be affected by the syndrome. can develop in the same way as their peers. If 47 chromosomes are observed in the muscular system, postural and speech disorders are observed.

Translocation Down syndrome the rarest cases, 3% of form of Down syndrome. In other variants, the extra chromosome/chromosome part is located next to the 21st chromosome pair, but in the case of translocation this excess is free and attaches to the chromosome pair.

So what causes the similar physical appearance?

Cells contain extra genetic material. This material excess, as with other anomalies, specifically It causes physical deformities and developmental problems and affects the appearance of the individual.

For Down syndrome, the extra genetic material in this 21st chromosome causes a physical change by preventing the development of certain connective and bone tissues, especially in the head region. A small nose, mouth and ears, almond-shaped eyes, short neck, rounded head shape in front, flat in the back (from the neck), short nails and white spots on the iris are the most notable physical features.

At the same time, these individuals are due to problems with muscle movements. they are more prone to weight gain. In fact, people with Down syndrome all have different skin, hair, and eye colors and are different from each other. The fact that the excess of the 21st chromosome causes such changes, especially in the head region, makes all individuals with Down syndrome look alike.

Mosaic affects in Down syndrome. on a cell and system basis We said there was change. In other words, individuals with Mosaic Down syndrome may have fewer physical symptoms compared to the normal type and translocation type, and the symptoms vary depending on which system is affected. For this reason, their facial features may not resemble other individuals with Down syndrome.

Thanks to Dilara Sarı for answering our question. You can also follow him on his social media accounts: Instagram | twitter | YouTube

Dilara will be answering our other questions about genetics shortly. Stay tuned…