Down syndrome is a disability that causes physical and mental development delays. Kids with down syndrome are born with an extra copy of the 21st chromosome. That is why down syndrome is also known as trisomy 21 syndrome.
The cause of the down syndrome is the abnormal act of chromosomes. Children get their DNA chromosomes from both parents. In a normal situation, each baby’s cell is supposed to receive 23 pairs of chromosomes. But in kids with down syndrome, one of them doesn’t separate properly.
That chromosome ends up with three copies. So there is an extra copy of chromosome 21. This extra chromosome is the cause of problems in the brain and physical development of the child. But the development problems of each child can vary widely.
So, don’t be surprised if you find some kids with down syndrome are very healthy. Meanwhile, some others need a lot of medical attention. The risk of having kids with down syndrome rises day by day. So, you better know about how it can affect kids and be prepared for it.
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Genetics for Down Syndrome
As has been mentioned above, normal human cells contain 23 pairs of chromosomes. Half of them come from the father and the rest from the mother. But for kids with down syndrome, there are cell division abnormalities that result in an extra of full chromosome 21.
But there are at least 3 genetic variations for down syndrome. Follow the following list to understand about them!
- Mosaic down syndrome
The first genetic variation of down syndrome is mosaic down syndrome. This is the rare form of down syndrome in which only some cells have an extra copy of chromosome 21. So, in the baby’s body, there are both normal and abnormal cells.
The mosaic of normal and abnormal cells is said to the result of abnormal cell division after fertilization. And after the baby is born, the baby will show the symptoms of kids with down syndrome like we already know.
- Translocation down syndrome
The next type of genetics from down syndrome is translocation down syndrome. This type of genetics results in the usual two copies of chromosome 21. But there is an additional genetic material of chromosome 21 translocated to another chromosome.
The translocation usually happens before or at the conception date. So there is no unusual being of chromosome 21. But there is another chromosome.
- Trisomy 21
This trisomy 21 is the most common genetic variation of chromosome 21. The abnormal cell division results in three copies of chromosome 21. It is developed during the process of sperm and egg cells that build the baby’s body.
The type of genetic variation is what determines the characteristic features and problems that happen to the kids with down syndrome.
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Down Syndrome Life Expectancy
Nowadays, the life expectancy of kids with down syndrome increased significantly. It is a lot higher than in 1960, where on average kids with down syndrome lived only for 10 years old. Indeed it is very heartbreaking for parents of kids with down syndrome. That their child has to be gone in a very short life span.
In the time span between 1980 to 2003, 93% of babies that were born as a baby with down syndrome lived more than one year old. But only 88% of them can survive until 20 years old. The rate of death of kids with down syndrome during their first year of life is quite high at that time.
But since 2007, there has been a significant rise in their life expectancy. And nowadays, kids with down syndrome can live up to 47 years old on average. But there are many behind factors that can determine how long kids with down syndrome can live.
The first factor that can affect the life expectancy of babies with down syndrome is birth weight. If the babies are born with very low weight, more likely they will die within the first month of life. Another factor is whether the babies have heart problems or not.
Based on the data, kids with down syndrome who were born with a congenital heart defect were five times more likely to die before one year old. Another finding of life expectancy of persons with down syndrome is the race. Babies from the African-American race who were born with down syndrome have a lower chance of surviving their first year of life.
- Chromosome down syndrome
Normal babies inherit genes half from the mother and half from the father. The total of the chromosomes should be 46. But in the majority of cases of down syndrome, the baby gets an extra chromosome 21. So, the total of the chromosome he/ she has is 47.
You should learn about karyotyping to know how abnormalities of the chromosome of kids with down syndrome can be detected. Before that, you can follow the explanation about the karyotype of down syndrome below.
- Karyotype down syndrome
A karyotype is used to get a picture of the structures of chromosomes. The word karyotype is also used to describe the process of analyzing chromosomes of a person’s body. The laboratory process will look through the karyotype pictures to find any abnormal numbers or structure of chromosomes.
- Down syndrome 21 trisomy
Down syndrome is also known as 21 trisomies. But how can you understand what 21 trisomy is in an easy explanation? Trisomy 21 or 21 trisomy can be explained by the existence of three copies of chromosome number 21, instead of two.
This can happen when 46 chromosomes from the mother and father are being divided. Instead of divided in half, an egg or sperm cell may keep both copies of chromosomes 21. So when the fertilization happens, the baby will end up with 3 copies of chromosomes 21. That is why it is called 21 trisomies or trisomy 21.
Treatment for Down Syndrome
Kids with down syndrome have to live with it for the rest of their life. So no treatment can cure down syndrome. On the other hand, some treatments can help kids with down syndrome to improve their condition.
The type of treatment mostly is physical therapy. In the treatment process, the kids will undergo an intervention program depending on the state of their condition. Some of them may include regular school, but some of them may need a special class to improve their abilities.
Test for Down Syndrome
There are diagnostic tests that can be used to diagnose down syndrome. The test can be performed as soon as the mother knows she was pregnant. But there is a risk of miscarriage as the test is performed inside the uterus.
But nowadays, doctors will offer many options for a screening test that you can choose by yourself. If you are not sure which test you should take, call your doctor to help you understand what are the pros and the cons of each test.
Down Syndrome Test Accuracy
The accuracy of each test is 99%. It is a very high number despite the high risk that should be faced as the result of the test. But doing the down syndrome test can be done when you are ready and already know all about the complication that comes after.
- Genetic test for down syndrome
A genetic test for down syndrome doesn’t have to wait until the baby is born. It can be even when the baby is still in your tummy. The test that is called Chorionic villus sampling (CVS) for example, is done by taking a sample from the placenta to test whether the baby has down syndrome or not.
Any type of genetic test for down syndrome can be performed between 10 to 18 weeks of pregnancy. You can discuss with your doctor when is the right time to perform the test to know the chance of you having kids with down syndrome.
- Prenatal testing down syndrome
The process to identify women at increased risk of having kids with down syndrome can be done before the estimated date of delivery. That is why the test is called prenatal testing. Different from the previous genetic test, this test has no risk of miscarriage.
Even if the accuracy of the result is not as high as the previous test, the doctors can identify any abnormality in the fetus by doing this test. So this prenatal test is quite popular and safe for both the mother and the baby.
- Down syndrome screening
The last type of test for identifying kids with down syndrome before they were born is by doing a screening test. A screening test is done in two phases. The first phase is performed between 10 to 14 weeks of pregnancy. The mother’s blood sample will be taken to identify the amount of fluid at the back of the baby’s neck.
In the second phase, the doctors will again take a blood sample of the mothers when they reach 15 to 20 weeks of pregnancy. The result of both blood tests will be combined to determine the rate of the baby having down syndrome.
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What are Baby Down Syndrome Sign?
Down syndrome can be identified during pregnancy state, so when the baby was born you can directly find the down syndrome signs. The same with what we can identify from kids with down syndrome, the babies have similar features too.
They have flat facial features, slant upward eyes, short neck, small ears, bulging tongue, and slightly bent fifth finger. If you find these signs on your newborn, then you have to know how to take care of them rightfully.
What are The Characteristic of children down syndrome?
There are some special characteristics of kids with down syndrome. For example, kids with down syndrome usually have a mid to low IQ score. They also have delayed speech compared to other children.
The same with all the signs that have been mentioned before, children with down syndrome developed similar facial features. And the most common characteristic of them is they have poor muscle tone.
So do you already understand more about kids with down syndrome now?