Laterality Sequence Defects

Did you know that different laterality sequence defects can be explained by the arrangement of the various organs and linked abnormalities? In some cases a laterality sequence defect maybe inherited in an autosomal dominant inheritance. A person with laterality sequence defect may have heart defects, poor growth known as “intrauterine growth retardation” (a baby who is smaller than normal during pregnancy and usually have a low weight at birth), and organ reversal.

Laterality Sequence defects may pass on from parent to child. This is known as an Autosomal Dominant Pattern. The gene for this is carried on one of the 22 pairs of numbered autosomal chrosomes. Therefore you only need one copy of the malformed gene (the gene doesn’t work right). This mutant gene is needed for the development of a laterality sequence. Upon my reading, I found out that a copy of CFC1 is found on chromosome 2 and is involved in development of the left-to-right axis in human development. I also read that CFC1 is a consequence of visceral Heterotaxy as well as an erratic group of congenital anomalies that include difficult cardiac abnormalities and situs inversus or situs ambiguous.

Autosomal Dominant Inheritance

First of all, genes are the blueprints for making matter, called proteins, our bodies need to develop and work properly. As you all know, a lot of our genes come in pairs, one of which comes from the mother and the other from the father.

Autosomal dominant inheritance means that the gene carrying a mutation is located on one of the autosomes (chromosome pairs 1 through 22). This means that males and females are equally likely to inherit the mutation. "Dominant" means that having a mutation in just one of the two copies of a particular gene is all it takes for a person to have a trait. When a parent has a dominant gene mutation, there is a 50 percent chance that any child he/she has will also inherit the mutation.

There are four possible combinations in the children. Two of the four, or 50 percent, have inherited the mutation. The other 50 percent have not inherited the mutation. These four combinations are possible every time a pregnancy occurs between these two individuals. The gender of the children (whether they are sons or daughters) does not matter. The chance is 50/50 for each pregnancy.

An important characteristic of dominant gene mutations is that they can have variable expression. This means that some people have milder or more severe symptoms than others. In addition, which systems of the body the mutation affects can vary, even in the same family. Another important characteristic of dominant gene mutations is that in some cases, they can have reduced penetrance. This means that sometimes a person can have a dominant mutation but not show any signs of disease. The concept of reduced penetrance is particularly important in the case of autosomal dominant susceptibility genes.

Some of the information noted above is from a various websites for which I noted below. I also copied and pasted some of the information for easy reading for my readers.
http://www.novelguide.com/a/discover/gegd_0002_0001_0/gegd_0002_0001_0_00239.html
http://www.novelguide.com/a/discover/gegd_0002_0001_0/gegd_0002_0001_0_00239.html