Columbia University Center for Precision Medicine and Genomics

Introduction to Genetics

Family traits

DNA is the genetic information contained in each and every cell of our bodies. The entire set of a person’s DNA is called the ‘genome’. Specific parts of our DNA are called ‘genes’. Genes inform our bodies about how to perform very specific functions. For example, some genes are important in informing the proper function of our kidneys, while others are important for normal function of our lungs.

Our DNA is inherited, or passed down from parents to their children. We inherit half of our DNA from each parent. This means we have two copies of each gene, one copy passed down from our mother and the second copy from our father.

The majority of our genetic information is similar in all people; however, there are also many differences between us. Most of the time, these differences are a part of what makes each human unique.

Genetic testing can look through each of the genes for changes (or mutations). Occasionally these changes can have an effect on our body function, as they can prevent a gene from working properly. These types of changes can cause or increase someone’s risk of developing certain illnesses.

Because we share our genetic material with our families, genetic testing can inform us and our families about certain illnesses that we may already have or may be at risk of having. This can help our doctors guide our treatment. Genetic testing can also help us in other ways by providing an answer for why we developed a certain illness, or help with family planning.