- Health A to Z
- Healthy Living
Advertisement
Down Syndrome Learning Center
Causes could include:
-
Anomaly of chromosome pair 21
|
In most cases, Down syndrome occurs when there is an extra copy of chromosome 21. This form of Down syndrome is called Trisomy 21. The extra chromosome causes problems with the way the body and brain develop.
|
 |
While Down syndrome is a chromosomal disorder, a baby is usually identified at birth through observation of a set of common physical characteristics. Babies with Down syndrome tend to be overly quiet; less responsive; with weak, floppy muscles. Fu...
|
 |
In approximately one to two percent of Down syndrome cases, the original egg and sperm cells contain the correct number of chromosomes, 23 each. The problem occurs sometime shortly after fertilization—during the phase when cells are dividing rapid...
|
 |
Down syndrome is usually the result of an extra copy of chromosome 21 (trisomy 21). As described earlier, Down syndrome may occur because of: nondisjunction within the sperm, or more commonly, the egg cell; genetic mosaicism, which occurs after co...
|
 |
In approximately one to two percent of Down syndrome cases, the original egg and sperm cells contain the correct number of chromosomes, 23 each. The problem occurs sometime shortly after fertilization—during the phase when cells are dividing rapid...
|
|
While Down syndrome is a chromosomal disorder, a baby is usually identified at birth through observation of a set of common physical characteristics. Babies with Down syndrome tend to be overly quiet, less responsive, with weak, floppy muscles. Fu...
|
