What is Down Syndrome

What is Down Syndrome? 

Down Syndrome is a genetic disorder when a baby has 47 chromosomes instead of 46 chromosomes in each cell. Genes come from the mother and the father and are the "instructions" of how the baby will grow and develop. Chromosomes- There are normally 23 pairs of chromosomes and each pair have one chromosome from the mother and one from the father. The 23rd pair of chromosomes determine if the baby will be a boy or a girl.

Cell Division and Fertilization are both causes of Down Syndrome. Normally a child receives 23 chromosomes from each parent. However, in Nondisjunction one of the parents have a cell that is 24 chromosomes instead of 23 and this causes the baby to have an extra 21 chromosome. That is also why Down Syndrome is called Trisomy 21. The 21st chromosome has failed to separate and therefore the baby now has three of these instead of two.

Nonjunction Trisomy 21 account for 95% of babies with Down Syndrome. There are two other types of Down Syndrome as well. Translocation Trisomy 21 is where there are three copies of the 21st chromosome but the third copy has attached itself to another chromosome. This is also the only type of Down Syndrome that could be inherited from a parent. Mosaicism is the least common form of Down Syndrome and only about 1% have it. This is when only some of the cells have the extra 21st chromosome.
Down Syndrome Features

Low Muscle Tone - Hypotonia is a condition where ones muscles appear relaxed and affects strength and movement of all muscles in the body. Most babies born with Down Syndrome have this condition. Low muscle tone complicates areas of development and make them harder for the baby to reach. Skills babies learn like rolling over, sitting, crawling, walking and even holding up babies heads can be challenging due to this condition. This can also affect baby eating skills and make trying solid foods also hard to do.
Nose - Down Syndrome babies usually have a flatter and smaller nose. Their nasal passages can also be smaller and cause them to be congested much easier than a baby born without Down Syndrome.
Eyes - Usually a baby born with Down Syndrome will have eyes that slant upward and have small folds at the inner corner.
Mouth - A baby born with Down Syndrome may have a smaller mouth and his or her tongue may stick out a little. Teeth usually come in later than normal and shaped a little different.