No parents want their child to be born with chromosome abnormalities.
So it is just natural for them to want to know about it as much as possible.
The statistics says that 1 in every 500 babies is born with some kind of abnormality of the structure or the number of the chromosomes. Numerous babies have physical or mental defects.
The chromosomes and the chromosomal abnormalities
The chromosomes are small, string like structures that can be found in the body’s cells and that come with the genes. Humans have about 20,000-25,000 genes that determine the traits, development and growth. Normally there are 23 pairs of chromosomes, 46 in total.
Causes of the abnormalities of the chromosomes
These abnormalities usually appear because of an error of the development of a sperm or an egg. At this moment it is not known what causes these. In some cases something goes wrong even before fertilization. The cells can divide incorrectly and as a result there can be too few or too many chromosomes.
When such a cell joins a normal cell the result will be a baby with an abnormality of the chromosomes. The most common kind of abnormality is known as trisomy. This means that a chromosome has three copies instead of only two. For instance in case of the Down syndrome there are three copies of chromosome 21.
Usually if the embryo has a chromosome’s abnormality, it won’t survive. This is when a miscarriage occurs. In many cases this happens very early, even before women know that they are pregnant. About 50% of the early miscarriages are caused by abnormalities of this kind.
Before fertilization
The problems of the chromosomes can also occur before fertilization. As a result the structure of the chromosomes will be altered. In this case the babies have the normal number of chromosomes. Nonetheless smaller parts of the chromosomes can be duplicated, deleted, inverted, exchanged or misplaced.
It is possible that in this case the chromosome problems have no effect if the baby has the entire chromosome. However in other cases the problems of this kind can result in a miscarriage or birth defects. Problems with the cell division appear after fertilization.
As a result of this problem with the chromosome the baby could have mosaicism. This means that the cells have different genetic makeups. For instance, in some cases the babies with Turner syndrome could be missing an X chromosome in some of their cells, but not all the cells.
In case of this chromosome problem the babies can be mildly affected. However the severity of the condition depends on the percentage of the affected cells. Sometimes people will never know that they have a problem of this kind, because they never had any obvious signs that there is something wrong.
There is a lot to know about chromosomal abnormality. However the parents shouldn’t really think about them unless they have to. There are some things that the parents shouldn’t research because they will only get scared and worried. You have to focus on the fact that the baby will be alright.
