Table of ContentsView AllTable of ContentsTypesCauses and Risk FactorsSymptomsScreeningLiving With Down SyndromeComplicationsOutlookNext in Down Syndrome GuideDown Syndrome: Symptoms and Intellectual and Physical Traits
Table of ContentsView All
View All
Table of Contents
Types
Causes and Risk Factors
Symptoms
Screening
Living With Down Syndrome
Complications
Outlook
Next in Down Syndrome Guide
Down syndrome is a lifelong genetic condition that begins to have effects before birth and can significantly impact many aspects of a person’s life.
People who have Down syndrome can experience physical effects as well as cognitive challenges. However, the severity of the condition varies from person to person, and many people living with Down syndrome can lead happy, productive, and healthy lives.
This article describes the types of Down syndrome, its causes, risk factors, symptoms, screening tests, and long-term outlook.
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Types of Down Syndrome
Down syndrome is congenital, which means that it is present at birth. In fact, Down syndrome is present at conception. The condition occurs when a fertilized egg has an extra copy of chromosome 21. Down syndrome is also called trisomy 21.
The types of Down syndrome differ based on chromosomal patterns, as follows:
The extra genetic material from the third copy of chromosome 21 causes the body to develop differently. This occurs whether a person has full trisomy 21, mosaic Down syndrome, or translocation.
This produces changes in the developing fetus’s physical features. Many of the changes are present at birth, and some can develop as the child grows into adolescence and adulthood.
Risk factors for Down syndrome include:
What Is Down Syndrome?
Down Syndrome and Genetics
The genetic pattern of Down syndrome occurs due to the presence of an extra copy of chromosome 21 in the parents' egg cell or sperm cell. A child should normally receive only one copy of each chromosome from each parent—resulting in two copies of each chromosome in every one of the child’s cells.
The process that causes an egg cell or a sperm cell to have an extra copy of a chromosome is called nondisjunction.It occurs during the formation of the egg and the sperm cell, prior to the embryo’s conception.
Down syndrome is not usually inherited—most people who have Down syndrome are the first in the family to have it, and their parents do not have the condition. However, it can be passed from parent to child if a person who has Down syndrome becomes pregnant or impregnates someone.
How Common Is Down Syndrome?Down syndrome affects approximately 1 out of every 675 live births.
How Common Is Down Syndrome?
Down syndrome affects approximately 1 out of every 675 live births.
What Are the Symptoms of Down Syndrome?
Several characteristic physical changes and symptoms occur due to Down syndrome. These changes are often recognizable at birth, but some children might not have obvious features until early childhood.
Many of the physical features—short stature, heavy build, and prominent eyelids—might resemble other family members who do not have Down syndrome, potentially making the condition less recognizable.
Effects of Down syndromeinclude:
People who have Down syndrome have a higher-than-average risk of developing Alzheimer’s dementia later in life. Sometimes people who have Down syndrome have blood cell abnormalities affecting white blood cells and red blood cells.
Down Syndrome: Symptoms and Intellectual and Physical Traits
Screening for Down Syndrome During Pregnancy
It is possible to identify Down syndrome during pregnancy. Testing and screening are not a standard part of prenatal care, but they can be done at the pregnant person’s request.
First Trimester
Second Trimester
Ultrasound testing can examine the fetus’s physical features, potentially identifying some characteristics that can occur with Down syndrome—such as heart malformations. This test can reliably identify developmental differences, but it does not rule in or rule out Down syndrome.
This test can definitively diagnose Down syndrome and specifically identify the type of Down syndrome.
Living with Down syndrome is a challenge for the whole family.Accommodations are often necessary to achieve learning goals and physical development during the toddler and school-age years. Many school districts offer accommodations for people who are living with Down syndrome,
Additionally, parents should seek the assistance of a multidisciplinary healthcare team to get the testing, therapy, and assistive devices needed to optimize quality of life.
Socializing is possible for people who have Down syndrome. Many people with Down syndrome can develop friendships and a supportive community.
People with Down syndrome can enjoy hobbies and other interests and often pursue those interests with lessons or classes. Many people with Down syndrome also have talents that they work to improve, such as art, music, acting, and more.
Complications of Down Syndrome
Examples of complications include:
Long-Term Outlook for Down Syndrome
In general, many people with Down syndrome can live long and healthy lives. The life expectancy is improving and is now over age 55.
Many people with Down syndrome can work in a job compatible with their physical and cognitive abilities. Support groups and advocacy organizations can often help find resources for job placement, recreational activities, transportation, and financial aid.
In general, people with Down syndrome are not able to live independently.Some may live with their families. Others may live in a group home or assisted living facility equipped to support their limitations and provide appropriate day-to-day help.
Down Syndrome: Facts and Statistics
8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.Facts about Down syndrome.National Institute for Child Health and Human Development.Who is at risk for Down syndrome?Antonarakis SE, Skotko BG, Rafii MS, et al.Down syndrome.Nat Rev Dis Primers. 2020;6(1):9. doi:10.1038/s41572-019-01437Hendrix JA, Amon A, Abbeduto L, et al.Opportunities, barriers, and recommendations in down syndrome research.Transl Sci Rare Dis. 2021;5(3-4):99-129. doi:10.3233/trd-200090Chicoine B, Rivelli A, Fitzpatrick V, Chicoine L, Jia G, Rzhetsky A.Prevalence of common disease conditions in a large cohort of individuals with Down syndrome in the United States.J Patient Cent Res Rev. 2021;8(2):86-97. doi:10.17294/2330-0698.1824Hamaguchi Y, Kondoh T, Fukuda M, et al.Leukopenia, macrocytosis, and thrombocytopenia occur in young adults with Down syndrome.Gene.2022;835:146663. doi:10.1016/j.gene.2022.146663Nikjoo S, Rezapour A, Moradi N, Nassiri S, Kabir A.Willingness to pay for Down syndrome screening: a systematics review.Med J Islam Repub Iran. 2022;36:149. doi:10.47176/mjiri.36.149Lemoine L, Benoît Schneider.Family support for (increasingly) older adults with Down syndrome: factors affecting siblings' involvement.J Intellect Disabil.2022:17446295221082725. doi:10.1177/17446295221082725
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.Facts about Down syndrome.National Institute for Child Health and Human Development.Who is at risk for Down syndrome?Antonarakis SE, Skotko BG, Rafii MS, et al.Down syndrome.Nat Rev Dis Primers. 2020;6(1):9. doi:10.1038/s41572-019-01437Hendrix JA, Amon A, Abbeduto L, et al.Opportunities, barriers, and recommendations in down syndrome research.Transl Sci Rare Dis. 2021;5(3-4):99-129. doi:10.3233/trd-200090Chicoine B, Rivelli A, Fitzpatrick V, Chicoine L, Jia G, Rzhetsky A.Prevalence of common disease conditions in a large cohort of individuals with Down syndrome in the United States.J Patient Cent Res Rev. 2021;8(2):86-97. doi:10.17294/2330-0698.1824Hamaguchi Y, Kondoh T, Fukuda M, et al.Leukopenia, macrocytosis, and thrombocytopenia occur in young adults with Down syndrome.Gene.2022;835:146663. doi:10.1016/j.gene.2022.146663Nikjoo S, Rezapour A, Moradi N, Nassiri S, Kabir A.Willingness to pay for Down syndrome screening: a systematics review.Med J Islam Repub Iran. 2022;36:149. doi:10.47176/mjiri.36.149Lemoine L, Benoît Schneider.Family support for (increasingly) older adults with Down syndrome: factors affecting siblings' involvement.J Intellect Disabil.2022:17446295221082725. doi:10.1177/17446295221082725
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Centers for Disease Control and Prevention.Facts about Down syndrome.National Institute for Child Health and Human Development.Who is at risk for Down syndrome?Antonarakis SE, Skotko BG, Rafii MS, et al.Down syndrome.Nat Rev Dis Primers. 2020;6(1):9. doi:10.1038/s41572-019-01437Hendrix JA, Amon A, Abbeduto L, et al.Opportunities, barriers, and recommendations in down syndrome research.Transl Sci Rare Dis. 2021;5(3-4):99-129. doi:10.3233/trd-200090Chicoine B, Rivelli A, Fitzpatrick V, Chicoine L, Jia G, Rzhetsky A.Prevalence of common disease conditions in a large cohort of individuals with Down syndrome in the United States.J Patient Cent Res Rev. 2021;8(2):86-97. doi:10.17294/2330-0698.1824Hamaguchi Y, Kondoh T, Fukuda M, et al.Leukopenia, macrocytosis, and thrombocytopenia occur in young adults with Down syndrome.Gene.2022;835:146663. doi:10.1016/j.gene.2022.146663Nikjoo S, Rezapour A, Moradi N, Nassiri S, Kabir A.Willingness to pay for Down syndrome screening: a systematics review.Med J Islam Repub Iran. 2022;36:149. doi:10.47176/mjiri.36.149Lemoine L, Benoît Schneider.Family support for (increasingly) older adults with Down syndrome: factors affecting siblings' involvement.J Intellect Disabil.2022:17446295221082725. doi:10.1177/17446295221082725
Centers for Disease Control and Prevention.Facts about Down syndrome.
National Institute for Child Health and Human Development.Who is at risk for Down syndrome?
Antonarakis SE, Skotko BG, Rafii MS, et al.Down syndrome.Nat Rev Dis Primers. 2020;6(1):9. doi:10.1038/s41572-019-01437
Hendrix JA, Amon A, Abbeduto L, et al.Opportunities, barriers, and recommendations in down syndrome research.Transl Sci Rare Dis. 2021;5(3-4):99-129. doi:10.3233/trd-200090
Chicoine B, Rivelli A, Fitzpatrick V, Chicoine L, Jia G, Rzhetsky A.Prevalence of common disease conditions in a large cohort of individuals with Down syndrome in the United States.J Patient Cent Res Rev. 2021;8(2):86-97. doi:10.17294/2330-0698.1824
Hamaguchi Y, Kondoh T, Fukuda M, et al.Leukopenia, macrocytosis, and thrombocytopenia occur in young adults with Down syndrome.Gene.2022;835:146663. doi:10.1016/j.gene.2022.146663
Nikjoo S, Rezapour A, Moradi N, Nassiri S, Kabir A.Willingness to pay for Down syndrome screening: a systematics review.Med J Islam Repub Iran. 2022;36:149. doi:10.47176/mjiri.36.149
Lemoine L, Benoît Schneider.Family support for (increasingly) older adults with Down syndrome: factors affecting siblings' involvement.J Intellect Disabil.2022:17446295221082725. doi:10.1177/17446295221082725
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