Genetic Issues With A/M

The eye is affected in about one-quarter of all inherited diseases, thus possible genetic causes of eye malformations must be considered. Congenital A/M can occur alone or with other birth differences. Geneticists use unusual findings in the eye, as well as other findings throughout the body, to help identify possible syndromes or causes of the disorder in an individual.

A/M has many different potential causes, including genetic conditions such as chromosomal disorders and single gene disorders.

Chromosomes are tiny structures that carry our genetic information and are arranged in 23 pairs in each cell of the body. One chromosome of each pair comes from the mother and the other from the father.  Each chromosome consists of thousands of genes, which are made up of DNA. The DNA is the genetic "alphabet" consisting of four letters: A, C, T and G. These letters create a series of three-letter "words" that combine and make up genes. Each gene has a specific function to encode the directions for the production of proteins in our bodies. Proteins are elements that do the different jobs our bodies require. A change in any of these "words" is known as a mutation. A mutation can lead to either abnormally made proteins or absence of the protein which then affects 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 cannot tell us if all the genes are working properly. It simply tells us there are no large pieces of chromosomes that are extra, missing or rearranged.

Sometimes, we cannot identify a syndrome in an individual to help explain the cause of A/M. Researchers are currently working on locating the gene or genes involved in normal eye development, which may lead to many answers about anophthalmia and enable geneticists to provide more accurate counseling and recurrence risks.