What makes us unique?
23.NOV.2023
Written by Anna Sanniti
Reviewed by Wendi Gill, CGC
It’s incredible to think that we are genetically different by only 0.1%, yet we are all so unique[1]. Now we will learn more about how the variation in our genome can influence our traits.
What is a genetic trait?
What are genetic mutations?
What is a genetic trait?
In genetics, a trait is a characteristic of someone that can be described or measured. Some examples include our height, eye color, blood pressure, and cholesterol levels[2]. Traits can be determined by genes, environmental factors, or a combination of both. Some traits, such as eye color, are based on our genetic code and are inherited from our parents. Other traits, such as cholesterol levels, are impacted by both genetic contributions and other environmental factors, such as diet and lifestyle.
What are genetic mutations?
Genetic mutations (also called genetic variants) are changes to the DNA sequence. Not all genetic mutations lead to an increased risk of developing disease. We often think of genetic mutations as something harmful-unwanted. However, the eye color trait described above is a consequence of genetic mutations (also called genetic variation). There are different types of genetic mutations, but the most common are caused by a single base pair change. For example, some individuals may have an ‘A’ at one position in their genome, while others may have a ‘G’. Remember that DNA is written in a language using four letters, known as bases: adenine (A), cytosine (C), guanine (G), and thymine (T).
Genetic variation can either have no effect (silent mutation) or may cause changes to the structure and function of a protein. Remember, the genetic code provides the instructions to build proteins. Proteins are molecules that carry out important jobs in our bodies, such as transporting nutrients, building new cells, and repairing damaged DNA. A change to the genetic code may cause the protein to behave differently, and in some cases, it may not work as effectively. Genetic mutations are happening in our cells all the time and can occur due to errors in DNA replication, exposure to UV light, or viral infections. Most mutations don’t affect our health and cannot be inherited[3]. If a genetic mutation is inherited, these are known as germline mutations, meaning they were present in the egg or sperm (i.e. your parents had this mutation). These mutations will be found in every cell in the body. Germline mutations are what give rise to our different physical characteristics. In some cases, these mutations can cause hereditary genetic disorders[3].
References
1. National Human Genome Research Institute Educational Resources. DNA. Online: Genome.gov
2. National Human Genome Research Institute Educational Resources. Trait. Online: Genome.gov
3. National Human Genome Research Institute Educational Resources. Mutations. Online: Genome.gov