Down Syndrome: Causes, Symptoms and Its Types

Down Syndrome

Down syndrome (also called Down’s Syndrome) occurs when a child is born with an extra copy of their 21st chromosome – hence their other name, trisomy 21. People with Down syndrome exhibit delays in development and learning disabilities.

There are many disabilities that in addition to reducing life expectancy, are lifelong. People affected with Down’s syndrome can live fulfilling and healthy lives. Despite the challenges associated with the syndrome in the past, recent medical advances, cultural and institutional support are creating opportunities for people with this condition.

What are the causes of Down’s syndrome?

The genes of both parents are passed on to the child in all cases of reproduction. Chromosomes carry the genes of both parents. Every cell in a baby has 46 chromosomes, so each cell produces 23 pairs of chromosomes. One-half of the chromosomes comes from the mother, and the other half comes from the father.

There is an issue with one of the chromosomes in children with Down syndrome. There is a third copy of chromosome 21, so instead of two, there is an extra copy. The extra chromosome affects the development of the brain and physical features.

In the United States, almost 1 in 700 babies are born with Down syndrome, according to the National Down Syndrome Society (NDSS). There are more than 10,000 American cases each year.

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What are the symptoms of Down’s syndrome?

You won’t notice any symptoms of carrying a child with Down syndrome if you undergo screening during pregnancy.

When the baby is born, he or she usually exhibits certain symptoms, including:

  • Flat facial features
  • Small ears and head
  • Short neck
  • Bulging tongue
  • Eyes that slant upward
  • Atypically shaped ears
  • Poor muscle tone

This can cause an infant to be born averaging in size, but it will be slower to develop than a child without it.

There are usually developmental disabilities associated with Down syndrome, but they’re usually mild to moderate. These delays may result in the following conditions:

  • Impulsive behavior
  • Poor judgment
  • Short attention span
  • Slow learning abilities

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Types of Down’s syndrome

The following are the three types of Down’s syndrome:

Trisomy 21

Every cell contains an extra copy of chromosome 21 when a person has trisomy 21. Approximately 2% of the population is affected by trisomy 21.


The condition Mosaicism occurs when an individual is born with a chromosome extra in some or all of his or her cells. The symptoms of mosaic Down syndrome are usually less severe than those of trisomy 21.


There is only an extra part of chromosome 21 in children with this type of Down syndrome. There are 46 chromosomes in total. There is an extra chromosome 21 in one of them.

Will my child have Down’s syndrome?

Parents with certain characteristics have a greater chance of having a baby with Down syndrome. The Centers for Disease Control and Prevention reports that a mother over the age of 35 has a higher likelihood of having a baby with Down syndrome. It becomes more likely the older the mother gets.

It is also found that paternal age is a factor. There is a two-to-one chance of having a child with Down syndrome if the father is over the age of 40, according to a 2003 study.

Additionally, the following parents have a greater likelihood of having a child with Down syndrome:

  • Those who have Down syndrome in their family
  • Individuals who have the genetic translocation

It is important to keep in mind that none of these factors ensures that your baby will have Down syndrome. Although statistically, and across a large population, you may have a greater chance of contracting it.

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Screening for Down’s syndrome during pregnancy

The United States provides routine prenatal screening for Down syndrome. Women over 35, fathers over 40, or people with a family history of Down syndrome should consider getting tested.

First trimester

You can find out whether you are carrying a child who has Down syndrome with an ultrasound evaluation and blood tests. Compared to tests conducted at later stages of pregnancy, these tests are more likely to be false-positive. After your 15th week of pregnancy, your doctor may recommend an amniocentesis if the test results aren’t normal.

Second trimester

The quadruple marker screen (QMS) can aid in detecting Down syndrome and other neurological conditions. It is performed during the 15th to 20th week of pregnancy.

It is considered a high risk for birth defects if any of these tests are not normal.

Additional prenatal tests

If your doctor suspects that your baby has Down syndrome, additional tests may be ordered. Some of these tests include:

  • Amniocentesis: Your doctor will examine a sample of your amniotic fluid to determine how many chromosomes your baby has. The test occurs after the 15th week of pregnancy.
  • Chorionic villus sampling (CVS): Placental cells are used to analyze fetal chromosomes. These are collected in the ninth to fourteenth week of pregnancy. There is a chance that it increases your risk of a miscarriage, but only by about 1 percent, says the Mayo Clinic.
  • Percutaneous umbilical blood sampling (PUBS, or cordocentesis): The umbilical cord will be removed and blood is taken to test for chromosomal defects. This is done after 18 weeks of pregnancy. Performing it is reserved for situations where all other tests are uncertain because it has a higher risk of miscarriage.

There is a risk of miscarriage involved in these tests, which motivates some women not to undergo them. An unplanned pregnancy would be better than having a child with Down syndrome.

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Tests at birth

After your child is born, your doctor will:

  • Conduct a physical examination of the baby
  • A karyotype test is needed to determine if a child has Down syndrome

Down’s syndrome Complications

Down syndrome babies may also have other physical issues, and they’re at higher risk for certain health conditions later in life.

Here are some potential complications:

  • Congenital heart defects
  • Hearing loss
  • Poor vision
  • Cataracts (clouded eyes)
  • Hip problems, such as dislocations
  • Leukemia
  • Chronic constipation
  • An interruption of breathing during sleep (sleep apnea)
  • Problems with thinking and memory (dementia)
  • Thyroid dysfunction (hypothyroidism)
  • Obesity
  • Slow tooth growth, resulting in chewing problems
  • Alzheimer’s disease later in life

Infections are also more common in such people. A respiratory infection, urinary tract infection, or skin infection may plague them.

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Down’s syndrome treatment

Down syndrome is not curable, but there are support and educational programs that can help both children and adults dealing with the condition. There are many programs available throughout the country, including those at the NDSS.

Many of the programs begin with early intervention. States are required by law to provide therapy to qualifying children and families. Your child will learn the following skills with the help of special educators and therapists:

  • Sensory skills
  • Social skills
  • Self-help skills
  • Motor skills
  • Language and cognitive abilities

These milestones are generally reached by children with Down’s syndrome. However, they may have slower learning curves than other children.

No matter how intelligent a child is with Down syndrome, school is an integral part of his or her life. Public and private schools offer integrated classrooms and special education opportunities for people with Down’s syndrome and their families. Through schooling, students with Down syndrome can develop valuable social skills that are crucial to their future.

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Does Down syndrome run in families?

There are three types of Down syndrome, each of which is genetic (relating to genes), but only one percent of cases are hereditary (passed down from parent to child). Nondisjunction trisomy 21 (nondisjunction mosaicism) and trisomy 21 (nondisjunction) are not caused by heredity. The hereditary component of Down syndrome occurs in about 1% of cases resulting from translocations.

Translocation risk is not associated with the mother’s age. There are most often sporadic – chance – events involved. It is estimated that one in three translocated chromosomes is inherited from one parent.

Do Down syndromes have a social impact?

There is increased integration of individuals with Down syndrome into society and local organizations, including schools, health care facilities, the workplace, social and recreational activities. There are varying degrees of cognitive delays among people with Down syndrome, ranging from very mild to severe. There is a wide range of cognitive delays in people with Down syndrome.

The development of medical technology has led to a longer life expectancy for people with Down syndrome. It was expected that children with Down syndrome would live to be nine years old in 1910. Biological progress led to the discovery of antibiotics, which resulted in an increase in the average survival age to 19 or 20.

Many adults with Down syndrome now reach the old age of 60 with the help of recent advances in clinical treatment, especially corrective heart surgery. The number of Americans interacting with individuals with Down syndrome is increasing, making it necessary for the public to become more educated and accepting of those with this condition.

Living with Down’s syndrome

Life expectancy for those with Down syndrome has increased dramatically over the past few decades. It was not uncommon for a child born with Down syndrome not to reach the age of 10 in 1960. Down syndrome patients are expected to live to an average age of 50 to 60 today.

Ideally, you should maintain a relationship with a medical professional who is familiar with the condition’s challenges if you’re raising a child with this syndrome. They need to guard against common infections such as colds in addition to larger concerns, such as heart defects and leukemia.

The quality of life for people with Down syndrome has become richer and longer in recent years. Even though they are often faced with unique challenges, they can still rise to the challenge. Their families must build a strong network of experienced professionals and understand their friends and families.