Down Syndrome

Overview

Down syndrome is a condition in which a person is born with an extra copy of chromosome 21. The condition is associated with intellectual disability, a characteristic facial appearance, and weak muscle tone in infancy. Down syndrome is the most common genetic cause of intellectual disability, the most common autosomal trisomy, and one of the most visible and universally recognized genetic syndromes.   

The range of medical conditions and abilities can vary widely for people with Down syndrome. Therefore, each person with this condition has their own strengths and challenges. In general, most people with Down syndrome have mild to moderate intellectual disabilities. Most can communicate verbally and take care of their basic needs (such as bathing, toileting, dressing, etc.). With appropriate support and treatment, many people with Down syndrome lead happy, productive lives. Within the past 25 years, the average lifespan for a person with Down syndrome has doubled, from 30 to 60 years. 

Improvements in healthcare, education, and public attitudes have greatly enhanced the lives of people with Down syndrome. This progress has given them more opportunities as valued members of their families and communities. More people with Down syndrome are finishing school, finding jobs, and forming meaningful relationships. 

Related Terms: Down syndrome is also called Trisomy 21 because it is caused by the presence of an extra copy (or three copies total) of chromosome 21. 

Types of Down Syndrome

There are three types of Down syndrome: trisomy 21 (nondisjunction), which accounts for 95% of cases, translocation, which accounts for about 3%, and mosaicism, which accounts for about 2%.

Trisomy 21

In Trisomy 21, each cell in the body has three separate copies of chromosome 21. 

Translocation Down Syndrome

In this type of Down syndrome, an extra part or a whole extra chromosome 21 is present. However, the extra chromosome is attached or "trans-located" to a different chromosome rather than being a separate chromosome 21. This type accounts for about 3% of people with Down syndrome.

Mosaic Down Syndrome

The word mosaic means mixture or combination. In this type of Down syndrome, some cells have three copies of chromosome 21, while other cells have just the typical two copies. People with mosaic Down syndrome may have fewer features of the condition given that only some cells in their body contain a third copy of chromosome 21. This type accounts for about 2% of people with Down syndrome. 

Characteristics of Down Syndrome

Down syndrome causes distinct physical and cognitive features that may vary by individual. These distinct physical signs of Down syndrome are usually present at birth and become more apparent as the child grows older. Common physical characteristics in individuals with Down syndrome may include:

• Low muscle tone 
• A smaller head and shorter neck
• Small folds of skin at the inner corners of the eyes 
• A flatter bridge of the nose 
• Eyes that tilt slightly upward 
• Small white spots, sometimes seen in the colored part of the eyes 
• Extra skin at the back of the neck 
• A single crease across the palm of the hand 
• Smaller pinky fingers
• A wider gap between the big toe and second toe, sometimes with a deep crease on the sole of the foot 

Related Health Effects

People with Down syndrome may have a variety of birth defects. About half of all affected children are born with congenital heart disease. Individuals with Down syndrome have an increased risk of developing several medical conditions, including hearing and vision problems, gastrointestinal issues, and celiac disease. The majority of adults with Down syndrome will begin to show signs of Down syndrome-associated Alzheimer’s Disease (DSAD) as they age. 

Causes and Risk Factors

Down syndrome usually occurs randomly during conception, leading to extra genetic material (a third copy of chromosome 21). It does not happen because of something that the parents did before or during pregnancy or due to environmental factors. We do not know for sure why Down syndrome occurs.

We do know that some factors can affect one’s risk of having a baby with Down syndrome. One factor is the age of a mother when she gets pregnant. The risk of having a baby with Down syndrome increases with age. Women who are 35 years or older when they become pregnant are more likely to have a pregnancy affected by Down syndrome than women who become pregnant at a younger age. However, most babies born with Down syndrome are born to mothers less than 35 years old, because there are many more births among younger women. 

Parents with one child with Down syndrome have a higher chance of having another child with Down syndrome, regardless of age. 

Diagnosis

There are two main kinds of tests that can check for Down syndrome during pregnancy: 

Screening tests help estimate the chance that a baby may have Down syndrome. 

During pregnancy, doctors may recommend screening tests such as:

• Ultrasounds
• Blood tests, such as Non-Invasive Prenatal Testing (NIPT)

These tests can suggest whether Down syndrome is more likely, but they cannot confirm it.

Diagnostic tests can confirm whether a baby has Down syndrome, but they are more invasive and carry a small risk of miscarriage.

To know for sure, doctors use diagnostic tests such as:

• Chorionic villus sampling (CVS)
• Amniocentesis

Several healthcare professionals may help with testing and explaining results, including obstetricians, genetic counselors, pediatricians, geneticists, and other specialists.  

Doctors cannot predict how Down syndrome will affect a child based on these tests alone, because every child with Down syndrome is different.

Treatment and Management

Down syndrome is a lifelong genetic condition. There is no cure or single, standard medicine that treats Down syndrome. Treatment focuses on managing associated health conditions such as thyroid issues, heart defects, or infections using targeted medical treatments. In addition, therapies and early intervention programs can help maximize development.

Early intervention for infants and children with Down syndrome can make a significant difference in improving their quality of life. Because each child with Down syndrome is unique, treatment will depend on the child's needs. As an individual with Down syndrome gets older and enters different stages of life, they may need different care or services. 

Ongoing services like healthcare, education, and life skills support are important for people with Down syndrome throughout their lives. Routine medical care and treating issues when needed can help promote good health throughout the lifespan.

Treatment for Infants and Children

The first years of life are an important period for growth and development. Children with Down syndrome may experience delays in physical, cognitive, language, social, and daily living skills. Early intervention services, including physical, speech, and occupational therapies, are important to help support development and learning beginning in infancy. 

The American Academy of Pediatrics (AAP) provides age-specific health supervision recommendations and family checklists for children and adolescents with Down syndrome, including guidance on cardiac, hearing, vision, thyroid, developmental, and sleep evaluations. 

Specialized growth charts developed for children with Down syndrome may help healthcare providers monitor growth patterns, nutrition, and physical development throughout childhood and adolescence. The Centers for Disease Control and Prevention (CDC) provides growth charts for use during routine health supervision and development monitoring. 

Children with Down syndrome and their families may need several specialists that can provide medical care for their child’s specific health needs. The healthcare team may include some of these experts:

• Primary care pediatrician to coordinate and give routine childhood care
• Pediatric heart specialist called a cardiologist
• Pediatric digestive system specialist called a gastroenterologist
• Pediatric specialist in treating hormone-related conditions called an endocrinologist
• Developmental pediatrician
• Pediatric nervous system specialist called a neurologist
• Pediatric ear, nose and throat (ENT) specialist, also called an otolaryngologist
• Pediatric eye doctor called an ophthalmologist
• Hearing professional called an audiologist
• Speech and language therapist called a speech-language pathologist
• Physical therapist
• Occupational therapist 

Because Down syndrome varies from individual to individual, care plans must be personalized based on their needs. 

Treatment for Adults

Adults with Down syndrome may have different healthcare needs than individuals without Down syndrome. Some medical conditions occur more often, while others occur less often, which may affect routine care and treatment approaches. Although healthcare guidelines exist for children with Down syndrome and are regularly updated, guidance for adults with Down syndrome has, until recently, been limited to Alzheimer's disease.

GLOBAL Down Syndrome Foundation has recently developed family-friendly healthcare guidelines for adults with Down syndrome. This resource includes information about preventive care, routine health screenings, mental health, aging, communication, and management of co-occurring medical conditions to help support health and quality of life throughout adulthood.

As a person with Down syndrome reaches adulthood, their healthcare needs may change. In addition to general health screenings recommended for all adults, ongoing care often includes monitoring for and managing conditions that are more common in adults with Down syndrome. Some individuals and families choose to seek care from an adult Down syndrome specialty clinic or a provider with specific experience in this area, if available.

Common co-occurring conditions in adults with Down syndrome can include vision and hearing loss, dental concerns, and hypothyroidism (low thyroid levels). Other conditions may include diabetes, celiac disease, and gastroesophageal reflux disease (GERD), as well as heart disease, stroke risk, and high cholesterol. Adults with Down syndrome may also be more likely to experience obesity, sleep apnea, mood or behavioral changes, Alzheimer’s disease (see “Caring for an Aging Individual with Down Syndrome” section below), and bone-related conditions such as spinal issues, arthritis, or osteoporosis. 

In addition to healthcare needs, supporting an adult with Down syndrome often involves planning for both current and future aspects of daily life. This can include considering living arrangements, opportunities for social and recreational engagement, access to support programs and employment, financial planning, and, when appropriate, legal considerations such as guardianship. 

Drug Therapy

Down syndrome is a genetic condition, not an illness or disease. There is no medication that cures or reverses Down syndrome. However, medications and medical treatments may be used to help manage associated health conditions that can occur in some individuals with Down syndrome.  

Living With Down Syndrome 

Caring for a Child with Down Syndrome

Speak with your healthcare provider about services available in your community. In many parts of the United States, there are programs to support infants and young children with Down syndrome and other developmental disabilities, typically from birth through age 3. Services often focus on improving communication, movement, social interaction, and daily living skills. Many programs include free evaluations to identify a child’s strengths and areas where support may be helpful. 

Explore educational opportunities early. Depending on a child’s learning style and support needs, schooling options may include general education classrooms, specialized instruction, classroom aides, or a blend of these approaches. Schools can develop an Individualized Education Plan (IEP), which outlines goals, accommodations, and services designed to support your child’s learning and development.  

Connect with other families who have lived experience with Down syndrome. Local organizations, national advocacy groups, and online communities can provide guidance, encouragement, and shared experiences. Friends and relatives can also play an important role in offering emotional support and understanding. For more information, see the “Community Support” section below.

Support the development of independence. Although children with Down syndrome may learn skills at a different pace than others, encouragement and regular practice can help them become more self-sufficient. Tasks such as getting dressed, preparing simple meals, cleaning, or organizing belongings can build confidence and life skills. Some families find that using routines or daily checklists helps children gain a stronger sense of responsibility and achievement. 

Plan ahead for adulthood. As the person with Down syndrome grows older, it can be helpful to begin exploring options for employment, housing, community programs, and recreational opportunities before they finish school. Supported living arrangements, vocational training, community jobs, and adult day programs often require advance preparation. Local agencies and support organizations may be able to provide information about available services and resources. 

People with Down syndrome can lead rich and meaningful lives. Many attend neighborhood schools, form close friendships, participate in community activities, work, and make personal choices about their lives. With encouragement, opportunities, and appropriate support, individuals with Down syndrome are capable of thriving in many different environments. 

Caring for an Aging Individual with Down Syndrome

Premature aging is a characteristic of adults with Down syndrome, as are dementia, memory loss, and impaired judgment that occur in those with Alzheimer’s disease. Adults with Down syndrome-associated Alzheimer’s disease (DSAD) have an increased risk of developing Alzheimer’s disease because of the extra copy of a gene on chromosome 21 that causes the buildup of amyloid protein in the brain. Research has shown that the changes in their brains on imaging start appearing in their 30s and dementia symptoms on average begin in their mid-50s. Regular medical monitoring and supportive care may help identify cognitive and behavioral changes over time. Families should look for associations between the type of behavior change, how often the behavior occurs, when the behavior occurs, and the persistence of specific behaviors that may be associated with dementia and memory loss. Research suggests that strategies to promote healthy aging in adults with Down syndrome, such as routine medical care and attention to lifestyle factors such as diet and exercise, can help to delay the development of dementia. Although much has been learned about DSAD, effective treatments are still needed.

Find Treatment

• To find Down Syndrome Clinics in the United States, visit Clinics listed by state.
• National Early Childhood Technical Assistance Center is run by the U.S. Department of Education and provides information and resources for parents and families looking for early intervention programs.
• Additional early intervention resources are available at The Early Intervention Provider.
• The U.S. Department of Education funds the Parent Center Network, which provides resources, contacts, and assistance for parents and families trying to navigate special education programs at the Parent Center Hub.
• Alzheimer Biomarkers Consortium-Down syndrome (ABC-DS) is a longitudinal study that follows adults with Down syndrome to identify risk factors for development of dementia.

NIH Resource

• National Institute on Aging’s Alzheimer's and Related Dementias Education and Referral (ADEAR) Center, 800-438-4380, adear@nia.nih.gov

Find Clinical Trials 

Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on Down Syndrome. 

DS-Connect®: The Down Syndrome Registry enables people with Down syndrome and their families to contribute to research studies, connect with researchers, and find resources and community events.

Community Support

The following organizations provide information, education, advocacy, support services, and community resources for individuals with Down syndrome, their families, caregivers, healthcare professionals, educators, and researchers:

National organizations:

• Black Down Syndrome Association (BDSA)  is a nonprofit organization that provides culturally responsive resources, support, and community for Black individuals with Down syndrome and their families.
• Down Syndrome Affiliates In Action (DSAIA) is a national membership organization that supports local, state, and regional Down syndrome organizations by fostering collaboration, leadership development, and resource sharing.
• Global Down Syndrome Foundation (GLOBAL) is a nonprofit organization that supports research, medical care, education, and advocacy to improve the lives of people with Down syndrome. GLOBAL has also supported the development of clinical care guidelines for adults with Down syndrome.
• International Mosaic Down Syndrome Association (IMDSA) provides information, education, and support for individuals with mosaic Down syndrome, their families, and healthcare professionals, while promoting awareness and research.
• National Association for Down Syndrome (NADS) is a nonprofit organization that provides information, educational resources, advocacy, and support for individuals with Down syndrome and their families.
• National Down Syndrome Adoption Network (NDSAN) is a free, U.S.-based registry that connects expectant and birth parents considering adoption with prospective adoptive families for children with Down syndrome.
• National Down Syndrome Congress (NDSC) is a nonprofit organization that provides advocacy, education, and support for individuals with Down syndrome and their families. NDSC offers information and resources from the time of diagnosis, whether prenatal or after birth, and throughout the lifespan.
• National Down Syndrome Society (NDSS) is a national advocacy organization that promotes the health, inclusion, and well-being of people with Down syndrome through public policy, education, public awareness, and community engagement.

Professional and educational resources:

• American Academy of Pediatrics (AAP) provides evidence-based clinical guidance for the healthcare of children and adolescents with Down syndrome.
• Association of University Centers on Disabilities (AUCD) is a national membership organization that supports university-based centers dedicated to improving the health, well-being, and community inclusion of people with developmental and other disabilities through research, education, service, and policy.
• National Task Group on Intellectual Disabilities and Dementia Practices (NTG) provides educational resources, caregiver support, screening tools, and guidance on aging and dementia for adults with intellectual and developmental disabilities, including people with Down syndrome.

Specialized support resources:

• Down Syndrome Diagnosis Network (DSDN) provides education, peer support, and community connections for parents and families following a prenatal or postnatal Down syndrome diagnosis.
• Down Syndrome – Autism Connection is a nonprofit organization that provides education, support, and resources for individuals with co-occurring Down syndrome and autism and their families.
• Locate a Down Syndrome Parent Organization by State is a directory of local, state, and regional Down syndrome organizations across the United States that helps individuals and families connect with community support and resources.

National partnerships and collaborations:

• Down Syndrome Consortium is an Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)-led public-private forum that brings together NIH, national Down syndrome organizations, healthcare professional organizations, self-advocates, researchers, and other stakeholders to promote communication and the exchange of information related to Down syndrome.

Additional Information

For new and expectant parents:

• Welcoming a Newborn with Down Syndrome: A New Parent's Guide is a free guide for parents and families of newborns with Down syndrome that provides information on adjusting to a diagnosis, infant feeding, medical care, early development, family relationships, and available support resources. The guide is available in English and Spanish.
• A promising future together: A guide for new and expectant parents (NDSS) provides information and support for expectant and new parents following a prenatal or postnatal Down syndrome diagnosis. 

 On healthcare and wellness:

• Healthcare Checklist for Families of Children and Adolescents with Down Syndrome (AAP) is a checklist to help families track recommended health supervision, developmental screenings, and preventive care.
• Medical Care of Adults With Down Syndrome: A Clinical Guideline (JAMA) is an evidence-based clinical practice guideline for the medical care of adults with Down syndrome, including recommendations for screening, prevention, and management of common health conditions.
• Down Syndrome Healthcare Guidelines Record Sheet (GLOBAL) is a tool for tracking recommended health screenings and preventive care throughout the lifespan.
• Aging and Down Syndrome : A Health & Well-Being Guidebook (NDSS) provides information on healthy aging, common health concerns, and planning for adulthood and older age.

On Autism and Down syndrome:

• Down Syndrome and Autism Spectrum Disorder (Autism Speaks) provides information on the co-occurrence of Down syndrome and autism spectrum disorder, including diagnosis and support. 
• Dual Diagnosis of Down Syndrome and Autism (NDSS) provides guidance on recognizing, evaluating, and supporting individuals with co-occurring Down syndrome and autism.

Considerations for communication:

• Language Guidelines (NDSS) provides guidance on respectful, person-centered language when discussing Down syndrome.

Note: This resource list is for informational purposes only. It is not comprehensive, and an organization’s inclusion does not constitute an endorsement by NIH.

Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.   

For decades, the NIH has funded and conducted Down syndrome research to advance our understanding of this genetic condition and to develop new treatments, interventions, and clinical approaches that improve health and quality of life. Nearly every NIH Institute and Center supports Down syndrome research, reflecting the broad range of co-occurring conditions that can affect individuals with Down syndrome across the lifespan. 

The INCLUDE (INvestigation of Co-occurring conditions across the Lifespan to Understand Down syndromE) Project was launched in June 2018 in support of a Congressional directive in the fiscal year (FY) 2018 Omnibus Appropriations. The directive called for a new NIH-wide research initiative on critical health and quality-of-life needs for individuals with Down syndrome. INCLUDE is investigating conditions that affect individuals with Down syndrome, such as Alzheimer’s disease/dementia, autism, cataracts, celiac disease, congenital heart disease, and diabetes. The INCLUDE Project has already stimulated research within its three main components of basic science, cohort building, and clinical trials for those with Down syndrome; the value of this investment is just starting to be realized. Through collaboration across many Institutes and Centers, NIH continues to accelerate scientific discovery, improve clinical care, and expand opportunities for people with Down syndrome to live longer, healthier, and more fulfilling lives.

DS-Connect®: The Down Syndrome Registry is a secure online survey-based tool developed for and by the Down syndrome community. It provides families with information about trusted research studies they can choose to join, as well as links to Down syndrome-specific healthcare guidelines, and other resources. When families share their privacy-protected demographic and health information with the registry, scientists can identify patterns in related health conditions and advance research that informs care, services, and future scientific discovery.

The NIH-funded Alzheimer Biomarkers Consortium-Down syndrome (ABC-DS) is a long-term study of adults with Down syndrome to identify early biomarkers that can predict the onset of Alzheimer’s disease. The goal is to use these biomarkers to develop clinical trials that will be effective in preventing the onset of DSAD. 

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies.