What are Genes?

Genes are chemical instructions that are passed through families. Genes encode many important functions for our body. Some genes act like blueprints and tell our body how to make brain structures, such as the cerebellum. Other genes act like instruction manuals for our body. They may tell parts of our body how to communicate with one another, how to get rid of toxic chemicals, or how to turn the food we eat into energy. We have two copies of most of our genetic instructions because we inherit one copy from our mother and another copy from our father.

Genes are spelled out with a chemical code. The chemical is called “DNA.” There are 4 different chemical “letters” in the DNA alphabet. Scientists have labeled the four different DNA letters “A,” “C,” “G,” and “T.”

The spelling of a particular genetic instruction can vary from person to person. Some of these variations are normal and don’t cause disease. For example, differences in eye color are due to differences in the DNA code. These types of spelling changes are considered to be benign (they don’t cause a problem). These benign spelling changes are sometimes called “polymorphisms.”

Other types of spelling changes can cause problems. Some spelling changes may make a gene stop working, while other spelling changes may tell a gene to start performing an abnormal function. Genetic ataxias are caused by spelling changes in genes that are very important to the structure and function of our cerebellum. These types of genetic changes can be passed through families in several different patterns.