Each gene has a specific function to encode the directions for the production of proteins in our bodies. Proteins are elements which do the different jobs our bodies require. A mutation can lead to either abnormally made proteins or absence of the protein which then afffects the development of the fetus during pregnancy. Single gene disorders occur as a result of a mutation in one gene on one or both of the chromosomes of a pair. This mutation changes the genetic information and therefore the blueprint for development, which leads to disease or birth defects.
Chromosomal disorders involve extra, or missing chromosomes or rearranged pieces of chromosomes.
This extra or missing information changes the blueprint for development. Because each chromosome houses thousands of genes, a normal chromosome result can not tell us if all the genes are working properly. It simply tells us there are no large pieces of chromosomes which are extra, missing or rearranged. The registry is compiling information on pregnancy, maternal medical and family histories, as well as environmental exposures.