PATHOLOGY

Detailed explanation-1: -Trisomy 21: About 95% of people with Down syndrome have Trisomy 21. With this type of Down syndrome, each cell in the body has 3 separate copies of chromosome 21 instead of the usual 2 copies.

Detailed explanation-2: -Also known as Down syndrome, trisomy 21 is a genetic condition caused by an extra chromosome. Most babies inherit 23 chromosomes from each parent, for a total of 46 chromosomes. Babies with Down syndrome however, end up with three chromosomes at position 21, instead of the usual pair.

Detailed explanation-3: -Chromosome 21 likely contains 200 to 300 genes that provide instructions for making proteins. These proteins perform a variety of different roles in the body. The following chromosomal conditions are associated with changes in the structure or number of copies of chromosome 21.

Detailed explanation-4: -Down syndrome (also known as trisomy 21) is an example of a condition caused by trisomy . People with Down syndrome typically have three copies of chromosome 21 in each cell, for a total of 47 chromosomes per cell. Monosomy, or the loss of one chromosome in cells, is another kind of aneuploidy.

Detailed explanation-5: -In most cases of Down syndrome, a child gets an extra chromosome 21-for a total of 47 chromosomes instead of 46. Rarely, the extra chromosome 21 attaches to another chromosome.