Down Syndrome

Down syndrome is a hereditary disorder in which one person is an extra copy of congenital chromosome 21. There are three signs of genetic mutation leading to Down's syndrome: 21 trisomy, 21 trisomy 21 trisomy 21 or trisomy 21 There are many ways to trisomy, where disability is affected. Once an egg or sperm brings an extra copy of chromosome 21, once the embryo is formed and begins to develop, chromosome 21 appears in every cell of the embryo. 21 Trisomy is the most common Down syndrome.

Mosaic is the least common form of Down's syndrome, accounting for only about 1% of all Down's syndrome cases. Studies have shown that Down's syndrome may be less characterized by Down syndrome than other types of Down's syndrome patients. However, people with Down Syndrome have broad capabilities and can not be generalized. In translocation, the total number of intracellular chromosomes is still 46 in about 4% of cases of Down's syndrome; however, extra whole or part of the copy of chromosome 21 is bound to another chromosome, usually chromosome 14 doing. The presence of all or a portion of chromosome 21 additionally leads to a distinguishing feature of Down's syndrome.

In Down's syndrome Down's syndrome, one is born with an extra copy of chromosome 21. And it is one of 23 human chromosomes. Scientists do not know why Down Syndrome is at high risk of Alzheimer's disease, but it may be associated with extra copies of chromosome 21. This chromosome contains the gene encoding APP, which is excised into beta-amyloid fragment in Alzheimer's disease and accumulates in plaques. Extra copies of chromosome 21 increase the number of beta-amyloid fragments in the brain