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Down syndrome, a condition where a person has an extra chromosome, affects 1 out of every 700 babies in the United States. This extra chromosome affects how a baby forms during pregnancy and how they function. Also known as Trisomy 21, Down syndrome causes challenges for someone born with it. Those born with Down Syndrome look and act differently than normal children, and have different abilities.

Types of Down Syndrome

There are three different types of Down syndrome. Trisomy 21 is the most common (95%) and is characterized by having a third copy of chromosome 21, rather than the usual two. Translocation Down Syndrome constitutes about 3% of those with the disease and occurs when an extra part or extra chromosome is present, but it is trans located rather than separate. Mosaic Down Syndrome affects about 2% of those with Down Syndrome. This means that while some individuals with Down Syndrome might have three copies of chromosome 21, some have the regular two copies.


There are two tests to detect Down Syndrome during pregnancy. A screening test can tell whether someone’s pregnancy has a higher risk of having Down Syndrome. They don’t, however, provide an absolute diagnosis. Diagnostic testing is usually done after a positive screening test. Diagnostic testing can detect whether the baby will have it or not. However. it is a huge risk for the mother and the developing baby. Some forms of diagnostic testing include amniocentesis, percutaneous umbilical blood sampling, and chorionic villus sampling.

Call to Learn More About Helping Down Syndrome Children and Teenagers

If you have a teen with Down Syndrome and are looking for programs to help them, contact the Valley Socials Program of West San Fernando Valley and West Los Angeles, California. We serve teens with many special needs and are conveniently based in West San Fernando Valley and West Los Angeles, also serving Encino, Calabasas, Tarzana, and Sherman Oaks. Call us at (818) 650-0889 and let us answer your questions today.