Understanding Genetics

By Pilar L. Magoulas. M.S., C.G.C. 

All ectodermal dysplasias are heritable or genetic disorders, which means that they can be inherited or passed on to children. However, it is possible for a child to be the first person in his or her family to be affected by an ectodermal dysplasia.

Chromosomes and Genes

• The body is composed of billions of cells. Within the cells, are small thread-like structures called chromosomes. We have 23 pairs of chromosomes – two of each. We inherit one set from our mother and one set from our father.
• All of the chromosomes together make up our entire genetic information and can be thought of as an encyclopedia or set of instructions for how our bodies function.
• Chromosomes are like individual volumes of the encyclopedia set. Chromosomes contain all of our genetic information, in the form of genes.
• Genes are the instructions that tell our bodies how to work properly. If there is a change in any of our genes, it may affect what that gene is supposed to do and may cause different health or medical problems.
• Genes are composed of DNA, which are the letters of the genetic alphabet.
• A gene is like a sentence in a book. If there is a change in any of the letters or if any of the words are missing, it will affect what that sentence was supposed to say.
• Similarly, misspellings of any of the genes can affect how the gene works and may cause problems with normal health and development.

Genetic Variants

• The ectodermal dysplasias are caused by changes or misspellings in our genes. These are often called “mutations”.
• Many genetic changes are unique to a family. However, even in families and individuals who have the exact same spelling change (mutation), there can be variability in how the condition affects each individual.
• Therefore, it can be difficult to predict, just based on the genetic test result, how the genetic change may affect a person.
• Altered genes may be inherited from a parent, or normal genes may become altered (changed) at the time of conception.
• It is important to remember that a person cannot choose or modify the genes that he or she has, therefore, there is nothing that parents did or did not do to cause these genetic changes to happen.

Pilar L. Magoulas, M.S., C.G.C. is a Certified Genetic Counselor and Assistant Professor, in the Dept of Molecular and Human Genetics at Baylor College of Medicine /Texas Children’s Hospital. She’s a member of the NFED Scientific Advisory Council.

Other genetic articles that may interest you:

• It’s All in the Genes
• What Does HED Look Like?