Sindrome de Down (Trisomia 21)

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In the present essay the genetic alteration denominated Down Syndrome, or trisomy 21 will be described. Also we will describe its symptoms, characteristics, and prevention.

Down Syndrome, or trisomy 21. It is produced by the presence of an extra chromosome (understood by chromosome as the structure containing the DNA) or a part of it.

Knowing this, we ask ourselves What causes Down Syndrome? Well, in most cases Down syndrome is caused by a random error in the cell division that occurs during the formation of the ovum of the mother or the sperm of the father. Because of this error, when fertilization occurs, the embryo has an additional third chromosome 21, or "trisomy 21" instead of the usual pair. Trisomy is defined as the lack of chromosome disjunction resulting in a germ cell with 24 chromosomes instead of 23 and then a zygote with 47 chromosomes. Down syndrome is one of the most common causes of congenital anomalies

This type of autosomal trisomy occurs more as maternal age increases, as shown by the fact that trisomy 21 occurs once about 1400 births in mothers aged 20-24 years; But approximately once in 25, in women 45 years of age and older

As for symptoms, Down syndrome vary from person to person and can range from mild to severe. Regardless of the severity of the condition, people with Down syndrome have a widely recognized appearance. The head may be smaller than normal and abnormally formed. For example, the head may be round with a flat area in the back. The inner corner of the eyes may be rounded rather than pointy. Common physical signs include: Decreased muscle tone at birth. Excess skin on the back of the neck. Flat nose. Separate joints between skull bones (sutures). Unique crease in the palm of the hand. Small ears. Small mouth. Eyes inclined upwards. Short, broad hands with short fingers. Physical development is often slower than normal. Most children who have Down syndrome never reach average adult height. Children may also have mental and social developmental delays. Knowing this, common problems can include: Impulsive behavior, impaired discernment, short attention span and slow learning

As people with Down syndrome grow and become aware of their limitations, they are likely to become frustrated and angry. Similarly, not all people will have the same conditions, each and every one of them can develop different anomalies or problems both physical and psychological. For example:

- Dementia can be observed

- Eye problems like cataracts (most children with Down syndrome need glasses)

- Vomiting early and profuse.

- Hearing problems, probably caused by regular ear infections

- Problems of the hip and risk of dislocation

- Prolonged (chronic) constipation problems

- Hypothyroidism

When we talk about prevention we must be realistic, Down syndrome can not be prevented, which is why experts recommend genetic counseling for people with a family history of Down syndrome who wish to have a child. As mentioned earlier, the risk for women to have a child with Down syndrome increases as they age and is significantly higher among women 35 years and older. Likewise, couples who already have a baby with this syndrome have a higher risk of having another baby with the same disorder, which is why parents should be tested for prenatal diagnosis. If they reveal a genetic defect, a complete and detailed advice is important.

To conclude, this essay was carried out in order to inform the causes, symptoms, and prevention of this genetic alteration that affects the newborn and has no cure, since in personal opinion, it is not a disease, but a condition Which physically and mentally incapacitate the individual for certain activities. However, there are many affected by this genetic condition that are able to carry out activities and work without any inconvenience because with the effort and dedication of their parents, they are able to develop great intelligence in different areas and areas of society.