Down Syndrome – Definition, Types, Causes, Symptoms And Treatments

Our bodies are made up of millions of cells, in each cell there are 46 chromosomes, the DNA in our chromosomes determines how we develop, and Down syndrome occurs when there is an extra chromosome, so they have 47 chromosomes in their cells instead of 46. ​​It occurs at conception, in all ethnic and social groups and for parents of all ages, it is nobody’s fault, there is no cure and it does not go away. Down syndrome is the most common chromosomal disorder that we know of, one in every 700-900 babies born worldwide will have this disorder.

What is Down syndrome?

It is a condition in which a child is born with an extra copy of their chromosome 21, hence its other name, trisomy 21, this causes delays and disabilities in physical and mental development. Many of the disabilities last a lifetime and can also shorten life expectancy. However, people with Down syndrome can live healthily and satisfactorily, recent medical advances, as well as cultural and institutional support for individuals and their families, provide many opportunities to help overcome the challenges of this condition.

Types of Down syndrome

Trisomy 21

This type is the most common of all cases (90% to 95%) and is also known as nondisjunction. This condition is not an inherited disorder (meaning that not all children born to the same group of parents will have Down syndrome). This type of syndrome occurs when the two chromosomes 21 that originate in the mother do not divide (or separate) and are incorporated into the egg or sperm (hence this type is also known as nondisjunction).

The fertilized egg is made of 47 chromosomes that disrupt the formation of a fetus when cells begin to divide and the extra chromosome replicates in every cell in the body.


This type (not considered inherited) is rarer than trisomy 21 in about 1% of cases and occurs when the extra chromosome replicates in some cells of the body. The rest of the cells where replication has not occurred is normal, this means that people with this type of Down syndrome have few characteristics and partial symptoms of the disease. It is caused by nondisjunction shortly after embryonic fertilization and effectively forms a mosaic pattern of normal and abnormal cells (some cells contain 47 chromosomes and others contain 46).


When one part of chromosome 21 fuses with another (most often chromosome 14), this type of Down syndrome occurs. A fetus will develop a normal set of chromosomes, but has one with an additional set of genes (partial chromosome material) of the copy of chromosome 21 attributed to it, also occurring in a very small percentage of cases (about 4%), partial fusion or segmental trisomy 21 can be inherited by a future child if a person reproduces with this type.

Down syndrome symptoms

People with Down syndrome often have different physical characteristics, unique health problems, and variability in cognitive development.


Although the chance of having a baby with Down syndrome can be estimated by screening during pregnancy, you will not experience any symptoms of having a child with this condition. At birth, babies with Down syndrome usually have certain characteristic signs, including:

  • Eyes that have an upward slant, oblique fissures, epicanthic skinfolds in the inner corner, and white spots on the iris.
  • Flat facial features.
  • Small head and ears.
  • Low muscle tone
  • Small stature and short neck.
  • Flat nasal bridge.
  • Unique and deep pleats in the center of the palm.
  • Protruding tongue.
  • Ears of atypical shape.
  • Large space between the big toe and the second toe
  • A single flexion groove of the fifth finger.

Developmental delays

People with Down syndrome generally have cognitive development profiles that suggest mild to moderate intellectual disability. However, cognitive development and intellectual capacity are highly variable.

  • Children with Down syndrome reach developmental milestones later than their peers.
  • There may be a delay in the acquisition of speech. A child may need speech therapy to help him gain expressive language .
  • Fine motor skills can also be delayed, they can take time to develop after gross motor skills have been acquired.
  • Impulsive behavior
  • Lack of criteria.
  • Short attention span.
  • Slow learning abilities .

On average, a child with Down syndrome:

  • Sits at 11 months.
  • Crawls at 17 months.
  • Walking at 26 months.

There may also be attention problems, a tendency to pass judgment, and impulsive behavior, but they may attend school and become active members.

Health problems

Sometimes there are general health problems that can affect any organ system or bodily function. About half of all people with Down syndrome have a congenital heart defect.

There may also be an increased risk of:

  • Respiratory problems.
  • Hearing difficulties.
  • Alzheimer disease.
  • Childhood leukemia.
  • Epilepsy.
  • Thyroid conditions.
  • Poor vision
  • Cataracts (cloudy eyes).
  • Hip problems, such as dislocations.
  • Chronic constipation
  • Sleep apnea (interrupted breathing during sleep).
  • Dementia ( thinking and memory problems ).
  • Hypothyroidism (low thyroid function).
  • Obesity.
  • Delayed tooth growth, causing problems with chewing.
  • There also appears to be a lower risk of hardening of the arteries, diabetic retinopathy, and most types of cancer.

What Causes Down syndrome?

In all cases of reproduction, both parents pass on their genes to their children, these genes are carried on chromosomes. When the baby’s cells develop, each cell is supposed to receive 23 pairs of chromosomes, for a total of 46 chromosomes, half of the chromosomes are from the mother and half are from the father.

In children with Down syndrome, one of the chromosomes does not separate properly and the baby ends up with three copies, or an extra partial copy, of chromosome 21, instead of two, this extra chromosome causes problems as the brain and cells physical characteristics develop.

According to the National Down Syndrome Society (NDSS), approximately 1 in 700 babies in the United States is born with Down syndrome, making it the most common genetic disorder in the United States.

Screening for Down syndrome during pregnancy

Screening is offered as a routine part of prenatal care, if you are a woman over 35, the father of your baby is over 40, or there is a family history of Down syndrome, you may want to get an evaluation.

First term

An ultrasound evaluation and blood tests can look for Down syndrome in your fetus, these tests have a higher false positive rate than tests done in later stages of pregnancy. If the results are not normal, your doctor may follow up with an amniocentesis after the 15th week of pregnancy.

second trimester

An ultrasound and quadruple marker test can help identify Down syndrome and other defects in the brain and spinal cord. This test is done between 15 and 20 weeks of pregnancy. If any of these tests are not normal, you will be considered at high risk for birth defects.

Additional prenatal tests

Your doctor may order additional tests to detect Down syndrome in your baby. These may include:

  • Amniocentesis. Your doctor takes a sample of amniotic fluid to check the number of chromosomes your baby has. The test is usually done after 15 weeks.
  • Chorionic villus sampling. Cells will be taken from your placenta to analyze the fetal chromosomes, this test is performed between week 9 and 14 of pregnancy, it can increase the risk of a miscarriage.
  • Percutaneous umbilical blood sampling. Your doctor will take blood from the umbilical cord and examine it for chromosomal defects. Performed after the 18th week of pregnancy, you have a higher risk of miscarriage, so it is performed only if all other tests are uncertain.

Some women choose not to undergo these tests due to the risk of miscarriage, preferring to risk having a child with Down syndrome than losing the pregnancy.

Birth tests

At birth, a physical exam is done on your baby and a blood test called a karyotype is ordered to confirm Down syndrome.

Treatment for Down syndrome

During the physical exam, a baby will also be evaluated for any obvious signs of possible problems. A baby with Down syndrome will be examined for medical problems, particularly with the heart, thyroid, and eyes.

Problems or defects detected and diagnosed early are generally better managed, ensuring that the first days of life are more comfortable and that the child can develop at a healthy rate.

Once it has been diagnosed and all relevant checks and tests have been performed, the doctor will develop a comprehensive treatment plan to ensure that the child remains as healthy as possible as he or she grows. Different stages will require different phases of treatment and services, the plan will focus on the stages of a child’s life and will also take into account the important things that can be prepared before adulthood.

Treatment throughout a person’s life involves regular checkups, physical therapy, speech therapy, occupational therapy, nutritional needs, and counseling . Regular medical check-ups are important to identify and monitor a person with the general health condition of Down syndrome, they are important from the moment of birth and throughout a person’s life. During the first year, eye problems in particular are common and will be carefully evaluated during check-ups.

Many people with Down syndrome are more likely to develop certain health problems and serious medical conditions, early detection is better for optimal treatment.

Physical treatment will also involve:

  • Medications : These can include antibiotics to treat infections and thyroid hormones to treat an underactive thyroid gland and supplements, among others related to an individual’s personal health.
  • Surgery: If a baby is born with birth defects, surgery may be highly recommended to correct defects of the heart or spine, as well as obstructions and problems with the intestine.

During the early stages, speech therapy and physical therapy are essential and can help ensure that a baby / child develops sufficiently to improve their quality of life during adulthood. It will take time and patience from everyone involved, but a child will learn to master a variety of skills.

Encouragement can go a long way, and parents are likely to be surprised at how much a baby or child with Down syndrome can accomplish. He or she may be slower to learn to talk, walk, or even eat alone, but they can and will do so over time. The important thing to keep in mind is that a child with Down syndrome is not incapable of developing, they will develop the generally accepted age-appropriate milestones in their own time with appropriate help and encouragement.

The occupational therapy may be beneficial since adolescence and as a young adult, learn how to live so self – sufficient and develop essential skills as necessary to obtain and maintain a potential income (work), can dramatically improve the quality of life of a person. During the teen years and early adulthood, in particular, sensitive emotions and issues can greatly benefit from counseling sessions by going through specific transition phases as they grow up.

Will someone with Down syndrome be able to lead an independent life?

To some extent, this depends on how severely someone with Down syndrome is affected. While some children may need to go to a school that caters for their special needs, many may go to a conventional school. Similarly, as they get older, many people can cope with some kind of work, they can also make friends and have relationships.

They will never be able to live completely independently. For some, arrangements such as sheltered housing with close availability of caregivers and support may be possible, and others may need much higher levels of support and care.

People with Down syndrome are not fundamentally different from others, they have the same aspirations and aspirations in life as all of us, including:

  • A good place to live.
  • Meaningful employment.
  • The opportunity to enjoy the company of friends and family.
  • Privacy.
  • A role in our community.

However, achieving these goals is more difficult for them than it is for everyone else, many people with Down syndrome likely need some form of support to help them achieve the kind of life that most people take for granted.

In the past, many people with this syndrome had not had the opportunity to develop their full potential, they had been separated from the rest of the community, living in segregated settings, such as institutions of care. Low expectations were placed on them and there were limited opportunities for learning and personal growth.

Today we recognize that growing up in families and communities, with the same rights and responsibilities as everyone else, is vital to the development of people with Down syndrome. To be part of a community, you must be in it, this means that people who have only experienced life in a segregated environment may find it difficult to be included in the larger community. Life for people who grow up being included in families and communities will be very different than it has been for those who have always lived in care facilities.

Encouraging children with Down syndrome to go to school with their peers in their community has many benefits. It opens the way for a smooth transition to adulthood and encourages meaningful inclusion in the community.

People with Down syndrome need opportunities to reach their full potential, just like all of us. When given these opportunities, they become valuable and productive members of their families and the community.

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Hello, how are you? My name is Georgia Tarrant, and I am a clinical psychologist. In everyday life, professional obligations seem to predominate over our personal life. It's as if work takes up more and more of the time we'd love to devote to our love life, our family, or even a moment of leisure.

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