Trisomy 21意思

Trisomy 21, also known as Down syndrome, is a genetic condition that occurs when a person has three copies of chromosome 21 instead of the usual two copies. This extra genetic material alters the development of the individual's body and brain, leading to the characteristic features and potential health problems associated with Down syndrome.

Down syndrome is the most common chromosomal condition diagnosed in children, and it occurs in approximately 1 in 700 to 1 in 1,000 births. It is not a disease, but a genetic variation that is present from conception. People with Down syndrome may have distinctive facial features, such as a flat face, almond-shaped eyes, and a small nose and mouth. They may also have intellectual disabilities, developmental delays, and an increased risk for certain medical conditions, including congenital heart defects, gastrointestinal problems, and hearing and vision issues.

Down syndrome is typically diagnosed at birth or shortly after, and individuals with the condition can lead healthy, fulfilling lives with the right support and interventions. This support can include early intervention services, special education, medical care, and community resources.