Today’s guest post on genetic syndromes comes from Rachel Nortz, who is contributing a post on the Down Syndrome.
Down Syndrome is a genetic disorder that is characterized by all or part of a third copy of the 21st chromosome. There are three different forms of Down syndrome: trisomy 21, translocation, and mosaicism. Trisomy 21 is the most common form of Down syndrome. This occurs when the 21st chromosome pair does not split properly and the egg or sperm receives a double-dose of the extra chromosome. Translocation (3-4% have this type) is the result of when the extra part of the 21st chromosome becomes attached (translocated) onto another chromosome. Mosaicism is the result of an extra 21st chromosome in only some of the cells and this is the least common type of Down syndrome. Continue reading Spotlight on Syndromes: An SLPs Perspective on Down Syndrome