What are Genes?
Written by: Katie Williams, MD - Pediatric Geneticist at the Center for Special Children
The Basics of our Genetics
Our genetic code is a massive set of instructions for our body. It is made up of over 3 billion specialized chemical “letters”. If you tried to record all the “letters” in our genetic code, you would need to type 60 words per minute, 8 hours per day, for about 50 years!
Our genetic code is written in a chemical code made up of a specialized material called deoxyribonucleic acid (or DNA for short). The long string of DNA winds into large structures called chromosomes. If our DNA is like a chemical string of yarn, the chromosomes would be the skeins. Each chromosome contains many individual instructions called genes. We are still learning a great deal about our genetic code, but over 20,000 genes have been identified.
Each of these genes provides instructions for critical components of our bodies called proteins. Proteins are the workhorses of our bodies and essential to develop and maintain our health. Some proteins provide structure to our body, like the pigment in our eyes, components of our hair, or the muscle in our heart. Other proteins direct the development and chemical signaling in our brain. Thousands of proteins are needed to break down and utilize nutrients from the foods we eat. We all depend heavily on our genes to make the proteins our body needs.
Why Genes Matter
Our genetic material must copy itself countless times as our body grows and develops throughout our life. There are many safety checks in place to ensure this code stays intact, but it is not a perfect system. In fact, changes to the genetic code are common. Many times, these changes are harmless, but other times the change is in a very important gene and the change prevents the body from reading the gene properly. For example, changes to our genetic code can lead to a malformed protein or the complete absence of a protein. When this happens, it can change how a part of our body develops or functions.
Genetic conditions are health issues that arise from a significant change to our genetic code. These changes can be small or large. When a child is found to have a genetic condition, that can help the family know what to expect moving forward. For example, genetic testing may help us know if a child is likely to outgrow their medical issues, if there are treatments for their symptoms, or if there are other medical issues that commonly go along with what parents have already noticed. This all helps us to better care for a child.
Genetic testing can also explain if a genetic condition is likely to be found in other family members. Some genetic conditions are due to a new gene change that occurred in just one child in a family, so it is unlikely that other family members may have it as well. Other genetic conditions come about due to the unique set of gene changes we inherit from our mother and father. In those instances, the family could have more than one child with the condition.
There are many types of genetic tests, so it is important to have a clear understanding of a child’s medical history and any genetic conditions that run the family. Together, this information guides us to the test that is most likely to find an explanation for the family. The decision to pursue genetic testing is a very personal one, so we encourage all families to ask questions and choose what seems right for them.
Genetic conditions are health issues that arise from a significant change to our genetic code. These changes can be small or large. When a child is found to have a genetic condition, that can help the family know what to expect moving forward. For example, genetic testing may help us know if a child is likely to outgrow their medical issues, if there are treatments for their symptoms, or if there are other medical issues that commonly go along with what parents have already noticed. This all helps us to better care for a child.
Genetic testing can also explain if a genetic condition is likely to be found in other family members. Some genetic conditions are due to a new gene change that occurred in just one child in a family, so it is unlikely that other family members may have it as well. Other genetic conditions come about due to the unique set of gene changes we inherit from our mother and father. In those instances, the family could have more than one child with the condition.
There are many types of genetic tests, so it is important to have a clear understanding of a child’s medical history and any genetic conditions that run the family. Together, this information guides us to the test that is most likely to find an explanation for the family. The decision to pursue genetic testing is a very personal one, so we encourage all families to ask questions and choose what seems right for them.