What is Down Syndrome (Trisomy 21)? Down syndrome (Trisomy 21) Made Easy

Summary

Down syndrome, or trisomy 21, is a genetic disorder caused by an extra chromosome 21. It affects both mental and physical development, with individuals exhibiting varying abilities and distinct facial features. Commonly associated with mild to moderate intellectual disability and speech delays, it occurs in about 1 in 700 births. There are three types: Trisomy 21 (95%), Translocation (3%), and Mosaic (2%). Prenatal detection is possible through screening and diagnostic tests, though no cure exists. Support and educational programs help individuals with Down syndrome and their families.

Takeaways

• 🧬 Down syndrome, or trisomy 21, is a genetic disorder caused by the presence of an extra chromosome 21.
• 👶 Typically, humans have 46 chromosomes, but individuals with Down syndrome have 47 due to the extra chromosome 21.
• 🧠 The extra chromosome affects the development of the body and brain, leading to mental and physical challenges.
• 🌟 People with Down syndrome exhibit a range of abilities and characteristics, with no two individuals being exactly alike.
• 🏥 Down syndrome is the most common chromosomal condition in the United States, occurring in about 1 in 700 births.
• 🔍 There are three types of Down syndrome: Trisomy 21 (95% of cases), Translocation Down syndrome (3%), and Mosaic Down syndrome (2%).
• 🩺 Prenatal tests such as screening and diagnostic tests can help detect Down syndrome during pregnancy.
• 🚫 Screening tests provide risk assessment, while diagnostic tests can confirm a diagnosis but carry more risk.
• 👨‍⚕️ Children with Down syndrome may have associated health issues like hearing loss, heart defects, and sleep apnea.
• 🏫 Support and educational programs are available to help individuals with Down syndrome and their families, focusing on skills development.

Q & A

What is Down syndrome?

Down syndrome, also known as trisomy 21, is a genetic disorder where a person has an extra copy of chromosome 21, which can cause both mental and physical challenges.

How does the presence of an extra chromosome affect a person with Down syndrome?

The extra chromosome 21 changes how the baby's body and brain develop, leading to various mental and physical challenges.

What is the significance of the term 'trisomy' in the context of Down syndrome?

The term 'trisomy' refers to the condition where an individual has three copies of a chromosome instead of the usual two, which is the case with chromosome 21 in Down syndrome.

What are the common facial features associated with Down syndrome?

Common facial features include a flattened face, almond-shaped eyes that slant up, a short neck, small ears, and a tongue that tends to stick out of the mouth.

How does Down syndrome impact a person's cognitive abilities?

People with Down syndrome usually have an IQ in the mildly-to-moderately low range and are slower to speak than other children.

What is the prevalence of Down syndrome in the United States?

Down syndrome occurs in about 1 in every 700 babies born in the United States, with approximately 6,000 babies being born with the condition each year.

What are the three types of Down syndrome?

The three types of Down syndrome are Trisomy 21 (95% of cases), Translocation Down syndrome (3% of cases), and Mosaic Down syndrome (2% of cases).

How do screening tests for Down syndrome work during pregnancy?

Screening tests, such as blood tests and ultrasounds, can indicate whether a pregnancy has a higher or lower chance of having Down syndrome without providing a definitive diagnosis.

What are diagnostic tests, and how do they differ from screening tests?

Diagnostic tests, such as Chorionic villus sampling (CVS), Amniocentesis, and Percutaneous umbilical blood sampling (PUBS), can confirm a Down syndrome diagnosis but are riskier for the mother and developing baby compared to screening tests.

Can the full impact of Down syndrome on a baby be predicted through tests?

Neither screening nor diagnostic tests can predict the full impact of Down syndrome on a baby; the extent of the condition's effects varies from person to person.

What support and educational programs are available for individuals with Down syndrome?

Support and educational programs for individuals with Down syndrome include special education and therapy services that help develop sensory, social, self-help, motor skills, and language and cognitive abilities.