Happy First Day of Spring!
Tuesday, May 21, 2023, is World Down Syndrome Day. On this day, we recognize all those affected by this condition, including family, friends, and co-workers.
Down syndrome is a genetic disorder that typically causes developmental delays and disabilities. It can also cause physical complications. DS occurs in about 1 in every 700 babies. Approximately 6,000 babies are born with Down syndrome in the United States each year. It should be noted the rate of Down syndrome cases in the US increased by about 30% between 1979 and 2003.
Three different types of Down syndrome are characterized by how abnormal chromosomal development happens in the cells.
Trisomy 21. This type occurs when there is a separate extra copy of chromosome 21. This is the most common type of the disorder, affecting about 95% of people with Down syndrome.
Translocation Down syndrome. This type happens when an extra copy or extra fragment of chromosome 21 is attached to a different chromosome rather than a distinct extra copy. This is a rare form, affecting only about 3% of people with Down syndrome.
Mosaic Down syndrome. In this type, some of the person’s cells have an extra copy of chromosome 21, but other cells have the usual two copies. The effects of the disorder tend to be milder in this type. Mosaic Down syndrome is the rarest type, accounting for only about 2% of cases.