Down Syndrome: What is it, its symptoms, what causes it?

Down syndrome is a genetically based disorder that is common in society. Although there are many complications due to this syndrome, individuals with Down syndrome can live a long and healthy life thanks to the medical facilities developed today.

What is Down Syndrome?

Down syndrome is a genetic disorder. Healthy people have a total of 46 chromosomes, 2 of which are sex chromosomes (XX or XY). Chromosomes are structures that contain a person’s DNA and are surrounded by protein. Chromosomes are located in the nucleus of the cell and control the functions of the cell. It exists in two copies, one from the mother and one from the father. In other words, the remaining 44 chromosomes, excluding the sex chromosome, are actually 22 pairs. People with Down syndrome have three copies of chromosome 21, which should have two copies as a result of some disruptions during cell division. Therefore, people with Down syndrome have 47 chromosomes in total instead of 46. Down syndrome is also called trisomy 21 because there are 3 copies of chromosome 21.

The severity of the disorder varies among people with Down syndrome. Some syndromic people have milder symptoms, while others may show severe symptoms. Intellectual disability may occur in people with Down syndrome. Additionally, syndromic children may be behind their peers in developmental milestones. In addition to its mental effects, Down syndrome can also cause various problems in organs and systems such as the digestive system and heart.

Being aware of the family of people with Down syndrome about this genetic condition and making educational and social life arrangements tailored to the needs of the syndromic person contributes positively to the quality of life of the syndromic individual.

What Are the Complications Due to Down Syndrome?

Individuals with Down syndrome may develop many different complications related to the syndrome. These complications may become more apparent as a person ages. Some of the complications that occur due to Down syndrome are as follows:

• Heart Defects: About half of babies born with Down syndrome have a defect in the heart. In some people, this defect can be life-threatening and may require emergency surgery to correct the defect.
• Digestive System Defects: Defects related to the digestive system, which include many organs such as the intestine, esophagus, and anus, are also common in individuals with Down syndrome.
• Immune Disorders: People with Down syndrome due to abnormalities in their immune systems; People are at risk for autoimmune diseases, some types of cancer, and infectious diseases.
• Sleep Apnea: Differences in bone and soft tissue structures in individuals with Down syndrome make these individuals prone to sleep apnea.
• Obesity: The risk of being obese for individuals with Down syndrome is increased compared to the normal population.
• Spine Problems: Some individuals with Down syndrome have an alignment disorder between the two spinal bones in the neck. People with this condition are at increased risk of spinal cord damage in situations such as tilting the head excessively backwards.
• Leukemia: There is an increased risk of leukemia in young children with Down syndrome.
• Dementia: The risk of dementia, or dementia as it is commonly known, is higher in individuals with Down syndrome. In people with Down syndrome who have dementia, symptoms begin around the age of 50.
• Other Problems: People with Down syndrome may experience various health problems ranging from endocrine disorders to dental problems, visual disorders to ear infections.

What are the symptoms of Down Syndrome?

The symptoms seen in Down syndrome vary greatly between individuals. Intellectual disability and developmental delay in people with Down syndrome can be mild, moderate, or severe. Again, while some of these individuals are physically healthy, some may have serious heart disease or other health problems.

Common symptoms in individuals with Down syndrome are as follows:

• flattened face
• short neck
• small head sizes
• tongue sticking out
• Almond-shaped, small, slanted eyes
• Ears that are unusually shaped or small in size
• Weakness in muscle tone
• Broad, small hands with a single line on the palm
• Short fingers and toes
• increased flexibility
• Small white dots (Brushfield dots) in the iris, the colored part of the eye
• Short

Characteristics such as height and weight in Down syndrome may vary between individuals. However, individuals with Down syndrome generally develop later than their peers and remain smaller than their peers at the end of their development.

Most individuals with Down syndrome have mild to moderate intellectual disability. Language development is delayed in these individuals and problems with both short- and long-term memory may occur.

What Causes Down Syndrome?

Down syndrome develops due to the presence of 3 copies of chromosome 21, which normally has to be present in two copies. The symptoms and complications associated with the syndrome are mainly caused by this genetic problem.

21. There are different mechanisms that can cause 3 copies of the chromosome. These mechanisms are:

• Trisomy 21: About 95% of Down syndrome cases are trisomy 21, in which there are three copies of chromosome 21 instead of two, and this condition occurs in all cells in the body. This condition occurs as a result of an abnormality in cell division in one of the sperm or eggs that make up the individual.
• Mosaic Down Syndrome: In Mosaic Down Syndrome, which is rare, the 21st chromosome is found in 2 copies in some cells and 3 copies in some cells. This occurs due to the normal and some abnormal divisions of the cells that make up the individual after fertilization.
• Translocation Down Syndrome: Down syndrome can also occur when part of chromosome 21 attaches to another chromosome, or is also known as translocated. Individuals with this type of Down syndrome, in addition to chromosome 21 in two copies, also carry chromosome 21 material attached to another chromosome.

Is Down syndrome hereditary? The question is often asked. Down syndrome is not a condition that is usually passed from parent to child. The syndrome occurs due to abnormal cell division that occurs in the early stages of fetal development in the womb. However, Translocation Down syndrome can be transmitted from parent to child. Translocation Down Syndrome accounts for approximately 3 – 4% of all Down syndrome cases. Additionally, only a small minority of cases of Translocation Down Syndrome are inherited in families. As a result, the probability of Down syndrome being hereditary is quite low.

There are some factors that increase the chances of parents having a child with Down syndrome. These risk factors can be listed as follows:

• Advanced Maternal Age: As the mother gets older, the likelihood of having a child with Down syndrome increases. The reason for this situation is that the eggs in older women also get older and, accordingly, the risk of problems in cell division increases. 35 can be considered as the limit for this age, which increases the risk in mothers. However, it should not be forgotten that younger mothers can also have a baby with Down syndrome.
• Being a carrier for Translocation Down Syndrome: Both parents can pass Translocation Down Syndrome to their child.
• Having a child with Down syndrome: In families that are translocation carriers and have previously had a child with Down syndrome, the risk of Down syndrome in subsequent children is increased. These families can be informed about the possibility of Down syndrome by receiving genetic counseling before deciding to have children again.

Nowadays, with the development of health services, individuals with Down syndrome can live for more than 60 years. Diagnosing Down syndrome early, screening for possible complications and intervening in these complications; It is very important for the individual with Down syndrome to live a healthy life. It is of great importance for families to be aware of Down syndrome in terms of issues such as receiving education according to the child’s special needs and organizing the social environment.

An individual with Down syndrome must be regularly checked by the necessary departments starting from birth. For this reason, it would be better to follow the individual with Down syndrome in a comprehensive hospital.