Down syndrome - Symptoms and causes - Mayo Clinic
Nov 12, 2024 · Down syndrome is a genetic condition caused when an unusual cell division results in an extra full or partial copy of chromosome 21. This extra genetic material causes the developmental changes and physical features of Down syndrome. The term "syndrome" refers to a set of symptoms that tend to happen together.
Down syndrome - Wikipedia
Down syndrome or Down's syndrome, [ 12 ] also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. [ 3 ] . It is usually associated with developmental delays, mild to moderate intellectual disability, and characteristic physical features. [ 1 ][ 13 ]
Down Syndrome | Birth Defects | CDC - Centers for Disease …
Oct 28, 2024 · Types. There are three types of Down syndrome. The physical features and behaviors are similar for all three types. Trisomy 21. With Trisomy 21, each cell in the body has three separate copies of chromosome 21.
Down Syndrome: Symptoms & Causes - Cleveland Clinic
Jan 31, 2023 · Down syndrome is a genetic condition where a person is born with an extra copy of chromosome 21. This means that they have a total of 47 chromosomes instead of 46. This can affect how their brain and body develop. People diagnosed with Down syndrome have happy and healthy lives with supportive care. Down syndrome can affect how your child develops.
Down Syndrome: Causes, Types, and Symptoms - Healthline
Nov 28, 2023 · Down syndrome (sometimes called Down’s syndrome) is a condition in which a child is born with an extra copy of their 21st chromosome — hence its other name, trisomy 21. This causes physical and...
Living with Down Syndrome | Birth Defects | CDC
May 16, 2024 · Down syndrome is the most common chromosomal condition diagnosed in the United States. Families and healthcare providers in the United States have learned over time how to improve care for people living with Down syndrome. Children with Down syndrome are living longer, many into their adult years.
Down Syndrome - NICHD - Eunice Kennedy Shriver National …
Nov 22, 2023 · Down syndrome is a set of cognitive and physical symptoms that result from having an extra chromosome 21 or an extra piece of that chromosome. It is the most common chromosomal cause of mild to moderate intellectual disabilities. People with Down syndrome are at risk for several other health conditions.
Down syndrome: MedlinePlus Genetics
Down syndrome is a chromosomal condition that is associated with intellectual disability, a characteristic facial appearance, and weak muscle tone (hypotonia) in infancy. All affected individuals experience cognitive delays, but the intellectual disability is usually mild to moderate.
About Down Syndrome - National Human Genome Research …
Jun 29, 2017 · Down syndrome is a chromosomal condition related to chromosome 21. It affects 1 in 800 to 1 in 1000 live born infants. What are the symptoms of Down syndrome? People who have Down syndrome have learning difficulties, mental disability, a characteristic facial appearance, and poor muscle tone (hypotonia) in infancy.
Down Syndrome - MedlinePlus
Jan 26, 2024 · Down syndrome is a condition in which a person has an extra chromosome or an extra piece of a chromosome. This extra copy changes how a baby's body and brain develop. It can cause both mental and physical challenges during their lifetime. Even though people with Down syndrome might act and look similar, each person has different abilities.