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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.
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 , …
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 | Birth Defects | CDC - Centers for Disease …
Dec 26, 2024 · Down syndrome is a genetic condition where a person is born with an extra chromosome. This can affect how their brain and body develop. People diagnosed with Down syndrome can lead healthy lives with supportive care.
Down Syndrome - StatPearls - NCBI Bookshelf - National Center …
Aug 8, 2023 · Down syndrome (trisomy 21) is a genetic disorder caused by the presence of all or a portion of a third chromosome 21. Patients typically present with mild to moderate intellectual disability, growth retardation, and characteristic facial features.
Facts, Myths, & Truths About Down Syndrome - NDSS
Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21. This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome.
About Down Syndrome - National Human Genome Research …
Jun 29, 2017 · When Down syndrome is suspected in a person, a genetic test called a chromosome analysis is performed on a blood or skin sample to look for an extra chromosome 21 (trisomy 21). Trisomy 21 means that each cell in the body has three copies of chromosome 21 instead of the usual two copies.
Trisomy 21 (Down Syndrome) - Children's Hospital of Philadelphia
What is Trisomy 21 (Down syndrome)? Trisomy 21 is the most common chromosomal anomaly in humans, affecting about 5,000 babies born each year and more than 350,000 people in the United States. Also known as Down syndrome, trisomy 21 is a genetic condition caused by an extra chromosome.
About Down Syndrome | National Down Syndrome Society (NDSS)
Apr 6, 2021 · Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21. This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome.
Genetics of Down syndrome - Wikipedia
Down syndrome is a chromosomal abnormality characterized by the presence of an extra copy of genetic material on chromosome 21, either in whole (trisomy 21) or part (such as due to translocations).