Downs+Syndrome



 Downs Syndrome, also known as Trisomy 21, is a gene mutation in which the 21st chromosome pair in the female egg is not necessarily a pair because it contains 3 chromosomes where one of them never divided. Once the mutated egg meets the normal sperm, the final count of chromosomes in the cell is 47 rather than the normal 46. This causes for the child to be diagnosed with the life long illness of Downs Syndrome.

Down syndrome also forms in two other genetic conditions: mosaicism and translocation. Mosaicism occurs when nondisjunction of chromosome 21 takes place in one of the initial cell divisions after fertilization causing a person to have 46 chromosomes in some of their cells and 47 in others.



Translocation, which accounts for 3 to 4 percent of cases of Down syndrome, occurs when part of chromosome 21 breaks off during cell division and attaches to another chromosome, usually chromosome 14. While the total number of chromosomes in the cells remains 46, the presence of an extra part of chromosome 21 causes the characteristics of Down syndrome.